1 VEGETATION AND NOISE ABATEMENT Disarikan oleh: soemarno, pdklp-ppsub-2012
1. Kebisingan adalah bunyi yang tidak diinginkan dari usaha atau kegiatan dalam tingkat dan waktu tertentu yang dapat menimbulkan gangguan kesehatan manusia dan kenyamanan lingkungan; 2. Tingkat kebisingan adalah ukuran energi bunyi yang dinyatakan dalam satuan Desibel disingkat dB; 3. Baku tingkat kebisingan adalah batas maksimal tingkat kebisingan yang diperbolehkan dibuang ke lingkungan dari usaha atau kegiatan sehingga tidak menimbulkan gangguan kesehatan manusia dan kenyamanan lingkungan; Keputusan Menteri Negara Lingkungan Hidup No. 48 Tahun 1996 Tentang : Baku Tingkat Kebisingan BAKU TINGKAT KEBISINGAN
The Federal Highway Administration (FHWA) prescribes a three-part approach for addressing roadway noise including: 1) source controls and quiet vehicles, 2) reduction measures within highway construction, and 3) developing land adjacent to highways in a way that is compatible with highway noise. Jalur hijau sepanjang jalan kampus UB Foto smno-kampus.ub.-Mei 2012
KEPUTUSAN MENTERI NEGARA LINGKUNGAN HIDUP NO. 48 TAHUN 1996 TANGGAL 25 NOPEMBER 1996 BAKU TINGKAT KEBISINGAN
KEPUTUSAN MENTERI NEGARA LINGKUNGAN HIDUP NO. 48 TAHUN 1996 TANGGAL 25 NOPEMBER 1996 METODA PENGUKURAN, PERHITUNGAN DAN EVALUASI TINGKAT KEBISINGAN LINGKUNGAN 1. Metoda Pengukuran Pengukuran tingkat kebisingan dapat diiakukan dengan dua cara : 1) Cara Sederhana Dengan sebuah sound level meter biasa diukur tingkat tekanan bunyi db (A) selama 10 (sepuluh) menit untuk tiap pengukuran. Pembacaan dilakukan setiap 5 (lima) detik. 2) Cara Langsung Dengan sebuah integrating sound level meter yang mempunyai fasilitas pengukuran LTMS, yaitu Leq dengan waktu ukur setiap 5 detik, dilakukan pengukuran selama 10 (sepuluh) menit. Waktu pengukuran dilakukan selama aktifitas 24 jam (LSM) dencan cara pada siang hari tingkat aktifitas yang paling tinggi selama 10 jam (LS) pada selang waktu 06.00 - 22. 00 dan aktifitas dalam hari selama 8 jam (LM) pada selang 22.00 - 06.00. Setiap pengukuran harus dapat mewakili selang waktu tertentu dengan menetapkan paling sedikit 4 waktu pengukuran pada siang hari dan pada malam hari paling sedikit 3 waktu pengukuran, sebagai contoh : - L1 diambil pada jam 7.00 mewakli jam 06.00 - 09.00 - L2 diambil pada jam 10.00 mewakili jam 09.00 - 11.00 - L3 diambil pada jam 15.00 mewakili jam 14.00 - 17.00 - L4 diambil pada jam 20.00 mewakili jam 17.00.- 22.00 - L5 diambil pada jam 23.00 mewakili jam 22.00 - 24.00 - L6 diambil pada jam 01.00 mewakili jam 24.00 - 03.00 - L7 diambil pada jam 04.00 mewakili jam 03.00 - 06.00 Keterangan : - Leq : Equivalent Continuous Noise Level atau Tingkat Kebisingan Sinambung Setara ialah nilai tertentu kebisingan dari kebisingan yang berubah-ubah (fluktuatif selama waktu tertentu, yang setara dengan tingkat kebisingan dari kebisingan yang ajeg (steady) pada selang waktu yang sama. Satuannya adalah dB (A). - LTMS = Leq dengan waktu sampling tiap 5 detik - LS = Leq selama siang hari - LM = Leq selama malam hari -LSM = Leq selama siang dan malam hari.
2. Metode perhitungan: (dari contoh) LS dihitung sebagai berikut : LS = 10 log 1/16 ( T1.10 01L5 +.... +T4.1001L5) dB (A) LM dihitung sebagai berikut : LM = 10 log 1/8 ( T5.10 01L5 +.... +T7.1001L5) dB (A) Untuk mengetahui apakah tingkat kebisingan sudah melampaui tingkat kebisingan maka perlu dicari nilai LSM dari pengukuran lapangan. LSM dihitung dari rumus : LSM = 10 log 1/24 ( 16.10 01L5 +.... +8.1001L5) dB (A) 3. Metode Evaluasi Nilai LSM yang dihitung dibandingkan dengan nilai baku tingkat kebisingan yang ditetapkan dengan toleransi +3 dB(A) Jalur hijau sepanjang jalan kebun teh Wonosari Foto: smno-malang-sept 2010
7 Kebisingan didefinisikan sebagai "suara yang tak dikehendaki, misalnya yang merintangi terdengarnya suara-suara, musik dsb, atau yang menyebabkan rasa sakit atau yang menghalangi gaya hidup. Diantara pencemaran lingkungan yang lain, pencemaran/polusi kebisingan dianggap istimewa dalam hal:  Penilaian pribadi dan penilaian subyektif sangat menentukan untuk mengenali suara sebagai pencemaran kebisingan atau tidak, dan  Kerusakannya setempat dan sporadis dibandingkan dengan pencemaran air dan pencemaran udara (Bising pesawat udara merupakan pengecualian). vancouver.ca/.../cclerk/970513/c itynoisereport/
8 Keluhan-keluhan tentang pencemaran di Jepang menurut jenisnya Keluhan-keluhan tentang endapan tanah dihilangkan dari Tabel karena sulit untuk menggambarkann ya. Sumber: Komisi Koordinasi Sengketa Lingkungan
9 Tiga Unsur dari Suara Apabila keyboard dari piano ditekan, seseorang menangkap "nyaringnya", "tingginya" dan "nada" suara yang dipancarkan. Ini adalah tolak ukur yang menyatakan mutu sensorial dari suara dan dikenal sebagai "tiga unsur dari suara". Sebagai ukuran fisik dari "kenyaringan", ada amplitude dan tingkat tekanan suara. Untuk "tingginya" suara adalah frekwensi. Tentang nada, ada sejumlah besar ukuran fisik, kecenderungan jaman sekarang adalah menggabungkan segala yang merupakan sifat dari suara, termasuk tingginya, nyaringnya dan distribusi spektral sebagai "nada". www.dosits.org/science/whati s/2.htm
10 Frekwensi dan Panjang gelombang Udara terdiri atas partikel-partikel yang beragam dimensinya. Semakit rapat partikel-partikel ini, tekanan udara semakin bertambah; semakin jarang partikel-partikel, semakin rendah tekanan udara. Gejala yang muncul akibat perubahan tekanan ini disebut sebagai gelombang suara. Suatu gelombang suara memancar dengan kecepatan suara dengan gerakan seperti gelombang. Jarak antara dua titik geografis (yaitu dua titik di antara tekanan suara maksimum dan suara murni ) yang dipisahkan hanya oleh satu periode dan yang menunjukkan tekanan suara yang sama dinamakan "gelombang suara", yang dinyatakan sebagai (m). Apabila tekanan suara pada suatu titik berubah secara periodik, jumlah berapa kali naik-turunnya periodik ini berulang dalam satu detik dinamakan "frekwensi", yang dinyatakan sebagai f (Hz). Suara-suara ber-frekwensi tinggi adalah suara tinggi, sedangkan yang ber-frekwensi rendah adalah suara rendah. Hubungan antara kecepatan suara c (m/s), gelombang dan frekwensi f dinyatakan : c = f x Panjang gelombang dari suara yang dapat didengar adalah beberapa sentimeter dan sekitar 20 m. Mutu suara, yang dipengaruhi oleh kasarnya permukaan-permukaan yang memantulkan suara, tingginya pagar-pagar dan faktor-faktor lainnya, akan berbeda sebagai perbandingan dari panjang gelombang terhadap dimensi obyek, karena itu masalahnya menjadi lebih rumit.
11 Gelombang sinusoidal How do you characterize sounds? If you had to describe a specific sound to a friend, what words would you use? If you can't think of any words, close your eyes and listen to the people around you talk. Are you able to tell who is talking without opening your eyes? How? What are the differences between the sounds that different people make? Perhaps you thought of describing a sound with the words loud or soft; high-pitched or low-pitched. These words describe, or characterize, how we perceive sounds. Scientists, on the other hand, describe sounds with characteristics that can be measured using instruments. We can relate characteristics that scientists measure to the words we use to describe the sounds we hear. When we talk about loud or soft, scientists talk about the intensity, or amplitude, of the sound. When we talk about the pitch of a sound, scientists use the word frequency. www.dosits.org/science/whatis/2.ht m
12 Garis bentuk Kenyaringan Intensity or Loudness Sound travels in a wave. The wave's amplitude is the change in pressure as the sound wave passes by. If you increase the amplitude of a sound, you are making it louder, just as you do when you turn up the volume on your radio. If you decrease the amplitude, you are making the sound softer (turning down the volume). Characteristics that scientists use to describe sound, such as amplitude, can be related to a picture of a wave. www.dosits.org/science/whati s/2.htm
13 Garis bentuk Kenyaringan Dikatakan bahwa batas perbedaan suara yang bisa terdengar oleh rata-rata orang adalah 20 - 20,000 Hz, tetapi bisa terdengarnya tersebut tergantung pada frekwensi. Tes-tes (hearing) psikiatris menghasilkan Garis bentuk Kenyaringan. Kurva menggunakan 1000 Hz dan 40 dB sebagai referensi untuk suara murni dan mem-plot suara referensi ini dengan tingkat-tingkat yang bisa terdengar dari kenyaringan yang sama pada berbagai frekwensi. Kenyaringan suara yang diterima oleh telinga manusia bervariasi karena dua sifat-sifat fisik yaitu tingkat tekanan suara dan frekwensi. Bahkan dalam lingkup yang bisa terdengar, frekwensi-frekwensi rendah dan tinggi sulit untuk ditangkap. Dibutuhkan kepekaan tinggi pada lingkup 1 - 5 kHz. Apabila tingkat kenyaringan dari suatu suara dikurangi, pada suatu titik tertentu, suara tidak lagi terdengar. Tingkat ini juga berbeda sesuai dengan frekwensi. Tingkat ini diindikasikan sebagai tingkat minimum yang bisa terdengar (garis titik-titik). Tingkat minimum yang bisa terdengar pada 20 dB atau lebih dipandang sebagai kesulitan pendengaran.
14 Pengaruh / Akibat- akibat dari Kebisingan Apabila suatu suara mengganggu orang yang sedang membaca atau mendengarkan musik, maka suara itu adalah kebisingan bagi orang itu meskipun orang-orang lain mungkin tidak terganggu oleh suara tersebut. Meskipun pengaruh suara banyak kaitannya dengan faktor-faktor psikologis dan emosional, ada kasus-kasus di mana akibat-akibat serius seperti kehilangan pendengaran terjadi karena tingginya tingkat kenyaringan suara pada tingkat tekanan suara berbobot A atau karena lamanya telinga terpasang terhadap kebisingan tsb. Noise health effects are the health consequences of elevated sound levels. Elevated workplace or other noise can cause hearing impairment, hypertension, ischemic heart disease, annoyance, sleep disturbance, and decreased school performance.
15 Jenis-jenis dari Akibat-akibat kebisingan TipeUraian Akibat - akibat badani ah Kehila ngan pende ngaran Perubahan ambang batas sementara akibat kebisingan, Perubahan ambang batas permanen akibat kebisingan. Akibat -akibat fisiolog is Rasa tidak nyaman atau stres meningkat, tekanan darah meningkat, sakit kepala, bunyi dering Akibat - akibat psikol ogis Gangg uan emosio na Kejengkelan, kebingungan Gangg uan gaya hidup Gangguan tidur atau istirahat, hilang konsentrasi waktu bekerja, membaca dsb. Gangg uan pende ngaran Merintangi kemampuan mendengarkann TV, radio, percakapan, telpon dsb.
16 Tipe-Tipe Kebisingan Jumla h kebisi ngan Semua kebisingan di suatu tempat tertentu dan suatu waktu tertentu. Kebisi ngan spesifi k Kebisingan di antara jumlah kebisingan yang dapat dengan jelas dibedakan untuk alasan- alasan akustik. Seringkali sumber kebisingan dapat diidentifikasikan. Kebisi ngan residu a Kebisingan yang tertinggal sesudah penghapusan seluruh kebisingan spesifik dari jumlah kebisingan di suatu tempat tertentu dan suatu waktu tertentu. Kebisi ngan latar belaka ng Semua kebisingan lainnya ketika memusatkan perhatian pada suatu kebisingan tertentu. Penting untuk membedakan antara kebisingan residual dengan kebisingan latar belakang.
17 Suara adalah gejala di mana partikel-partikel di udara bergetar dan menyebabkan perubahan- perubahan dalam tekanan udara, karena itu intensitasnya dinyatakan sebagai tekanan suara. (Pascal adalah suatu unit [Pa]) dan energi yang diperlukan untuk getaran (juga dinamakan "tenaga suara dari sumber ", unit-unit watt [W]). Bila dinyatakan dalam Pascal, intensitas dari suara dinamakan "tekanan suara" dan menggunakan suatu unit referensi dari 20 Pa. Ini hampir sama dengan tekanan suara dari suara minimum yang ditangkap oleh telinga manusia. Tingkat tekanan suara didefinisikan sebagai 10x logaritma rasio dari tekanan suara efektif pangkat dua terhadap tekanan suara referensi efektif (20 Pa), dan dinyatakan dengan formula di bawah ini. Pendekatan ini diterima demi mudahnya anotasi, seperti - misalnya - suatu suara dengan 100 dB akan mempunyai tekanan suara sebesar 100.000 kali tekanan suara referensi dengan seterusnya menjadi terdiri dari banyak digit. Unit-unit itu adalah decibel (dB).
18 www.co.san- juan.wa.us/.../scenicrdmanual.asp x When planting the roadside, it is important to relate the arrangement and location of plants to the natural patterns of existing vegetation. The following guides will be helpful to achieve compatible relationships: 1. Plants should not be planted in geometric or uniform patterns, nor randomly scattered in a meaningless pattern. 2. Plants should be informally grouped in masses and clumps, with attention given to combinations which will provide diversity and contrast. 3. Space trees so when mature they will be proportional in size with surrounding vegetation. 4. Arrange plants so their edge is uneven and closer to the roadside in some locations and further away in others.
19 Demikian pula, intensitas suara didefinisikan secara kwantitatif sebagai tingkat kekuatan suara karena kekuatan suara dari unit-unit sumber (10 - 12 W). Seperti halnya dengan tingkat tekanan suara, unit-unit di sini menggunakan decibel. Dalam menilai kenyaringan suara, perlu mempertimbangkan perbedaan cara bagaimana suara ditangkap karena frekwensi, seperti dijelaskan dalam 1.4. Untuk itu, alat-alat ukur tingkat kebisingan menggunakan rangkaian penyesuaian frekwensi yang meng-asimilasikan kepekaan telinga manusia terhadap kenyaringan. Karakteristik penyesuaian frekwensi umumnya digunakan karakteristik A. Tingkat kenyaringan yang didapat sesudah penyesuaian frekwensi ini dinamakan "Tingkat tekanan suara berbobot A (tingkat kebisingan)".
20 Karakteristik frekwensi dari alat-alat ukur tingkat Kebisingan
21 Tingkat percentile (LAN, T) Kenyaringan kebisingan fluktuasi dengan waktu, karena itu perlu mempertimbangkan fluktuasi selama satu periode waktu ketika menilai tingkat tekanan suara berbobot A. Dua indeks populer adalah tingkat percentile dan tingkat tekanan suara berbobot A yang sepadan dan kontinyu. Tingkat kebisingan yang, untuk N% periode dari waktu yang diukur, sama atau lebih besar dari tingkat tertentu, dinamakan "Tingkat percentile N-persen". Variabel ini dinyatakan sebagai LAN dan suatu tingkat 50% (LA50) diambil sebagai titik tengah, 5% (LA5) sebagai batas atas dari lingkup 90% dan 95% (LA95) sebagai batas bawah dari lingkup 90% yang sama. Dalam pengukuran yang menggunakan faktor waktu aktual, praktek pada umumnya adalah mengambil contoh tingkat tekanan suara berbobot A pada interval waktu yang konstan, peroleh distribusi frekwensi kumulatifnya, kemudian mendapatkan tingkat percentile spesifik. Pada umumnya, dalam penilaian kebisingan lingkungan, sebaiknya mengambil 50 atau lebih contoh pada interval 5 detik atau kurang.
22 Tingkat tekanan suara berbobot A yang sepadan dan kontinyu-(LAeq) Tingkat tekanan suara berbobot A yang sepadan dan kontinyu banyak dipakai di seputar dunia sebagai indeks untuk kebisingan. Itu didefinisikan sebagai "tingkat tekanan suara berbobot A dari kebisingan yang fluktuasi selama suatu periode waktu T, yang dinyatakan sebagai jumlah energi rata-rata". Itu dinyatakan dengan formula di bawah ini P0: Tekanan suara referensi (20 Pa) PA: Tekanan suara berbobot A (untuk waktu A) dari kebisingan target (Pa) Periode waktu adalah dari waktu t1 sampai waktu t2, sedangkan jumlah contoh-contoh tingkat tekanan suara berbobot A adalah n.
23 Tingkat tekanan suara berbobot A yang sepadan dan kontinyu
24 Tingkat Ekspos Terhadap Suara (LAE) Tingkat ekspos terhadap suara digunakan untuk menyatakan kebisingan satu kali atau kebisingan sebentar-sebentar dalam jangka waktu pendek dan kontinyu. Variabel mengubah jumlah energi dari kebisingan satu kali menjadi tingkat tekanan suara berbobot A dari kebisingan tetap 1-detik yang kontinyu dari energi sepadan. Karena kebisingan kereta api dapat dianggap sebentar- sebentar, "kebijakan untuk mengatasi kebisingan dalam penambahan atau penyempurnaan jalur kereta api dalam skala besar (Jawatan Lingkungan Jepang, Des. 1995)" adalah dengan mengukur tingkat ekspos terhadap suara dari setiap kereta api yang lewat dan mendapatkan tingkat tekanan suara berbobot A yang sepadan dan kontinyu. T0: Waktu referensi (1 detik) t1 - t2: Waktu yang diperlukan untuk lewatnya satu kereta api
26 Formula untuk mendapatkan tingkat tekanan suara berbobot A yang sepadan dan kontinyu - dari tingkat peng-eksposan suara dari setiap kereta api yang lewat adalah sbb: T: Waktu (detik) yang ditargetkan untuk LAeq. Dari jam 07:00 sampai dengan 22:00 adalah 54,000 detik. Dari jam 22:00 sampai dengan 07:00 adalah 32,400 detik. Tingkat kekuatan sepadan juga dapat dicapai dengan menggunakan kekuatan rata-rata dari suatu tingkat ekspos terhadap suara (LAE) dan jumlah n kereta api sebagai berikut:
27 Tingkat Kebisingan Terbobot yang Diterima secara Sepadan dan Kontinyu (WECPNL, Jepang) Tingkat Kebisingan Terbobot yang Diterima secara Sepadan dan Kontinyu (WECPNL) adalah suatu ukuran yang diusulkan oleh organisasi penerbangan sipil Internasional (ICAO)untuk menilai ekspos yang kontinyu terhadap kebisingan jangka panjang dari berbagai pesawat terbang. Perhitungannya rumit, tetapi WECPNL yang digunakan untuk peraturan lingkungan hidup di Jepang didefinisikan dengan formula yang disederhanakan sbb: LA: Kekuatan rata-rata dari tingkat-tingkat tinggi kebisingan pesawat 10 dB atau jauh lebih besar dari kebisingan latar belakang. N: Jumlah pesawat yang berangkat tiap jam. N1: 24:00 - 07:00, N2: 07:00 - 19:00, N3: 19:00 - 22:00, N4: 22:00 - 24:00
28 Propagasi Suara (Rambatan Suara) Kekuatan suara dari sumber dan Tingkat Kekuatan Suara Suara dipancarkan apabila suatu sumber bergetar, tetapi kenyaringan dari suara yang dipancarkan berubah tergantung pada intensitas dari sumber. Intensitas ini didefinisikan sebagai energi suara yang dipancarkan dari sumber dalam 1 detik dan dinamakan "kekuatan suara dari sumber (P)" (unit- unit dari watts [W]). Tingkat indikasi untuk intensitas dari kekuatan suara ini dinamakan "tingkat kekuatan suara (PWL)". Seperti terpampang dalam 2.1, tingkat kekuatan suara sama dengan tingkat tekanan suara. Tetapi, di mana tingkat tekanan suara mengekspresikan kenyaringan suara yng dimonitor dalam suatu titik sembarangan, tingkat kekuatan suara mengekspresikan intensitas dari kekuatan akustik yang dipancarkan oleh suatu sumber.
29 Propagasi Suara Pada suatu titik berjarak r meter dari sumber suara sederhana, hubungan antara tingkat kekuatan suara (dB), tingkat intensitas suara IL (dB) dan tingkat tekanan suara SPL (dB) adalah sbb. SPL=IL=PWL - 20log r- 11 (Lapangan bebas) SPL=IL=PWL - 20log r- 8 (Lapangan setengah bebas) Yang dimaksudkan disini ialah bahwa, apabila tingkat kekuatan suara tidak dapat diukur secara langsung, tingkat kekuatan suara dari sumber dapat diperkirakan dari tingkat tekanan suara yang diukur pada suatu titik yang jauh dari sumber. Itu juga merupakan formula dasar yang digunakan secara terbalik untuk meramalkan kenyaringan dari suara yang menyebar ke dalam lingkungan, dari tingkat kekuatan suara.
30 PENGARUH DAN AKIBAT DARI KEBISINGAN Meskipun pengaruh suara banyak kaitannya dengan faktor-faktor psikologis dan emosional, ada kasus-kasus dimana akibat-akibat serius seperti kehilangan pendengaran terjadi karena tingginya tingkat kenyaringan suara pada tingkat tekanan suara berbobot A dan karena lamanya telinga terpajan terhadap kebisingan itu. Berikut jenis dari akibat kebisingan : TipeUraian Akibat lahiriah Kehilangan pendengar an Perubahan ambang batas sementara akibat kebisingan, perubahan ambang batas permanen akibat kebisingan Akibat fisiologis Rasa tidak nyaman atau stress meningkat, tekanan darah meningkat, sakit kepala, bunyi dering Akibat psikolo gis Gangguan emosional Kejengkelan, kebingungan Gangguan gaya hidup Gangguan tidur atau istirahat, hilang konsentrasi waktu bekerja, membaca dan sebagainya. Gangguan pendengar an Merintangi kemampuan mendengarkan TV, radio, percakapan, telpon dan sebagainya.
31 Decibels Decibel (dB) adalah kwantitas logaritmis yang dipakai sebagai unit-unit tingkat tekanan suara berbobot A. Ini dilakukan untuk dua alasan: pertama untuk menyederhanakan plot-plot multipel, ke dua untuk secara kira-kira menyebandingkan kwantitas logaritmik dari stimulus untuk stimulus akustik yang diterima telinga manusia dari luar. Untuk menilai kebisingan, perlu untuk menghitung tambahnya atau kurangnya tingkat tekanan suara berbobot A rata-ratanya dan sebagainya. Ini memerlukan pengetahuan dasar tentang perhitungan logaritma.
32 Highway Traffic Noise In recent years, highway traffic noise - the unpleasant, unwanted sounds generated on our nation's streets and highways - has been of increasing concern both to the public and to local, National and regional officials. At the same time, modern acoustical technology has been providing better ways to lessen the adverse impacts of highway traffic noise. Some of acoustical techniques are now being employed by government agencies, highway planners and designers, construction engineers, and private developers. www.wsdot.wa.gov/.../commonquestion
33 NOISE REDUCTION www.nonoise.org/.../highway/traffic/traff ic.htm Vegetation, if it is high enough, wide enough, and dense enough that it cannot be seen through, can decrease highway traffic noise. A 200-foot width of dense vegetation can reduce noise by 10 decibels, which cuts in half the loudness of traffic noise. It is often impractical, however, to plant enough vegetation along a road to achieve such reductions. But, if dense vegetation already exists, it could be saved. If it does not exist, roadside vegetation can be planted to create a psychological relief, if not an actual lessening of traffic noise levels.
34 Sound and Noise As we all know, sound is created when an object moves: the rustling of leaves as the wind blows, the air passing through our vocal chords, the almost invisible movement of the speakers on a stereo. The movements cause vibrations of the molecules in air in waves like ripples on water. When the vibrations reach our ears, we hear what we call sound. Sound is quantified by a meter which measures units called decibels (dB). For highway traffic noise, an adjustment, or weighting, of the high- and low- pitched sounds is made to approximate the way that an average person hears sounds. The adjusted sounds are called "A-weighted levels"(dBA). The A-weighted decibel scale begins at zero. This represents the faintest sound that can be heard by humans with very good hearing. The loudness of sounds (that is, how loud they seem to humans) varies from person to person, so there is no precise definition of loudness. However, based on many tests of large numbers of people, a sound level of 70 is twice as loud to the listener as a level of 60.
36 To achieve a reduction in noise emissions the Agency is: Ensuring that when a road needs a new surface, the most appropriate noise reducing surfaces are used where noise is a particular concern. Specifying quieter surfaces as a matter of course where new roads are to be built or existing roads improved. Identifying sites for the provision of noise mitigation such as noise barriers and double- glazing. Researching tyre/road noise in partnership with vehicle standard authorities and the tyre industry. Working towards improved performance in noise control during construction/maintenanc e activities. www.highways.gov.uk/aboutus/1085 0.htm
37 Causes of Traffic Noise The level of highway traffic noise depends on three things: (1) the volume of the traffic, (2) the speed of the traffic, and (3) the number of trucks in the flow of the traffic. Generally, the loudness of traffic noise is increased by heavier traffic volumes, higher speeds, and greater numbers of trucks. Vehicle noise is a combination of the noises produced by the engine, exhaust, and tires. The loudness of traffic noise can also be increased by defective mufflers or other faulty equipment on vehicles. Any condition (such as a steep incline) that causes heavy laboring of motor vehicle engines will also increase traffic noise levels. In addition, there are other more complicated factors that affect the loudness of traffic noise. For example, as a person moves away from a highway, traffic noise levels are reduced by distance, terrain, vegetation, and natural and manmade obstacles. Traffic noise is not usually a serious problem for people who live more the.500 feet from heavily traveled freeways or more than l00 to 200 feet from lightly traveled roads.
38 How Traffic Volume Affects Noise A 2000 vehicles per hour B 200 vehicles per hour A sounds twice as loud as B.
How Speed Affects Traffic Noise A 55 miles per hour B 15 miles per hour A sounds twice as loud as B. Aneka kendaraan bermotor jalan raya
Determining noise Impact Highway traffic noise is never constant. The noise level is always changing with the number, type, and speed of the vehicles which produce the noise. Traffic noise variations can be plotted, as shown by the graph below. It is usually inconvenient and cumbersome to use such a graph to represent traffic noise in this manner. A more practical method is to convert the noise data to a single representative number. Statistical descriptors are almost always used as a single number to describe varying traffic noise levels. The two most common statistical descriptors used for traffic noise are L10 and Leq. L10 is the sound level that is exceeded 10 percent of the time.
How Sound Travels Sound is caused by changes in air pressure. For example, when a mallet strikes a drum the drumhead begins to move back and forth (vibrate). As the drumhead moves down, air is pulled toward it, and as the head bounces back up it pushes air away. This creates changes in air pressure that move (or propagate) away from the drum, eventually striking our eardrum. These changes in pressure are known as sound waves. There are a number of factors that affect the propagation of sound. The most important include: distance from source; obstacles such as barriers and buildings; atmospheric absorption;wind direction and speed; temperature and temperature gradient; humidity; precipitation;reflections; and ground absorption. It is important to understand that noise does not always decrease as one moves away from a noise source. The above factors can work to increase or decrease noise levels. For example, at short distances (up to 160 feet) the wind has a minor influence on the measured sound level. At distances greater than 1,000 feet from a noise source, noise can become louder on the downwind side by as much as 20 dB, while on the upwind side levels can drop by 20 dB (depending on wind speed and distance). Other things to consider include the fact that while barriers may act to reduce high frequency sounds, low frequency sounds are difficult to reduce using obstacles or barriers. Additionally, while soft ground surfaces and the atmosphere are effective at absorbing mid-frequency and high frequency noise, these factors do not tend to reduce low frequency noise to the same degree. This means that as one moves away from the source, low frequencies often become much more prominent.
43 Noise Compatible Reduction Techniques - Physical Responses Topography Sound waves are affected by the terrain - whether hilly or flat - between the source and the receiver. A berm or hill will block sound and diminish its intensity. A ditch or gulley deflects the sound and depending on its depth and dimension will diminish the sound and/or cause a change in its path. Where hills are available, constructing noise sensitive uses behind the hills helps reduce sound problems. www.fhwa.dot.gov/.../noise/ncp/ncp_curr.htm Taman untuk meredam kebisingan
The Surface "Propagation medium" describes the area between the sound source and the receiver, including the type of ground surface (Exhibit 2). For instance, a fence reflects or deflects sound according to its height, thickness and material. Sound is affected by the type of surface, as well. Porous surfaces, like dirt or grass, absorb some sound; surfaces not so porous, like asphalt or concrete, will reflect some sound affecting how it's heard by the human ear.
45 www.avtreefarm.com/files/soun d-barrier.htm Planting a Sound Barrier Vegetation can be used to barrier the effects many problems including noise pollution. As with plantings for wind or visual barriers, the selection and arrangement of the plant material is key to a successful outcome.
46 Planting a Sound Barrier Noise reduction is achieved by either deflection or absorption of the noise or a combination of the two. Most hardscape barriers work by deflecting sound (example 1in pic.). To be effective they should be close to the source of the noise as safety allows. With these barriers vegetation serves to soften the visual effect of the barrier and reduce the reverberation of sound. Earthen berms are often used in combination with trees and shrubs to deflect and absorb sound when the available space is limited. Vegetation alone can be used where adequate space is available. To be effective the planting must be multiple rows to about 40 ‑ 75' in depth. Care also must be taken to plant the first row at 50' from a roadway or any area ‑ that should not be subject to extra snow deposits. Conifers or evergreen broadleaf plants will naturally provide the best year around noise reduction. Deciduous trees and shrubs can be added to the planting for variety and added summer noise reduction
47 PEMILIHAN VEGETASI Vegetation should be selected for site conditions with special attention to plant selection guidelines section. It is also important to incorporate fast growing plants and long lived plants for a quick and long lasting barrier. Shrubs: Plant in rows closest to the sound. Chose dense or thicket forming shrubs that tolerate salt or deicing chemicals and air pollutants. Caragana arborescens ; Philadelphus spp.; Potentilla fruticosa; Symphoricarpos spp. Conifers: Trees that retain lower branches will be most effective. Abies concolor; Juniperus spp. Barisan pepohonan di sepanjang jalan yang sunyi Foto: smno-malang-okt 2010
Deciduous trees: Taller trees should be selected for the center of the vegetative barrier. Fast growth rate can be considered to provide a more effective barrier more quickly. Smaller trees especially those with attractive flowering and form work well on the inside of the barrier for both visual and sound effect. Acer platanoides Acer saccharinum Aesculus hippocastanum Eleagnus angustifolium Fraxinus americana Gleditsia triacanthos and its varieties Juglans nigra Malus species (for inside rows as flowering sensitive to high levels of air pollutants) Populus spp. Prunus spp. Robinia pseudoacacia Salix spp. www.for.gov.bc.ca/.../HEALTH/GFHS0004.HTM
Concrete barriers and vegetation The engineering of these walls acoustic absorbents basa composción in the walls of two modules in which concrete is introduced along with the vegetation and topsoil must retainer of water to provide moisture Between the two there is an air chamber which further contributes to the sound insulation required. www.metrolight-es.com/eng_catalogo-barreras-a...
Wooden barriers Protective barrier against the noise produced in Nordic wood Thanks to the perfect acoustic isolation enclosure for tight joints Extensive range of finishes as the final position of the front panels There is also another kind of anti screens manufactured in wood (logs) This is a double-walled enclosures housing land in the interior. www.metrolight-es.com/eng_catalogo-barreras-a...
Purpose of Noise Compatible Land Use Planning (NCP) Commercial, Office, Retail, or Industrial Uses Commercial, office, retail or industrial uses next to highways experience improved accessibility and appreciate easy access to transportation arteries. Visibility is better for customers and deliveries, as well. These land uses are not negatively affected by the noise and they can serve to buffer residential or other sensitive uses from roadway generated sound. Vegetation may be planted to further buffer commercial uses from residential areas. Exhibits 1 and 2 show examples of commercial and other uses next to roadways. www.fhwa.dot.gov/.../noise/ncp/ncp_curr.htm
Open Space Community planners should actively seek opportunities to reserve undeveloped land and open space in locations where future roadways may be constructed. Open space allows sound to diminish before reaching sensitive receivers. Open space strategies may be used in combination with other strategies including commercial uses or noise reducing construction methods for buildings. Walking and bike paths and other recreational activities are options in the open space. www.fhwa.dot.gov/.../noise/ncp/ncp_curr.htm
Distance The greater the distance between the source of the sound and the receiver, the lower the noise level. Distance can be achieved by providing open space, as with recreational uses or publicly owned property that creates a buffer (such as state right-of-way). Local ordinances can require "setbacks," which mandate the locations for the front line of buildings. Setbacks reduce the impact of traffic noise if they are sited so as to allow enough space between the roadway and the receiver for sound to dissipate to acceptable levels www.fhwa.dot.gov/.../noise/ncp/ncp_curr.htm
55 Effect of roadside vegetation on the reduction of traffic noise levels C.M. Kalansuriya1, A.S. Pannila1, D.U.J Sonnadara2 1Electro Technology Laboratory, Industrial Technology Institute 2Centre for Instrument Development, Department of Physics, University of Colombo A study was carried out to determine the effect of roadside vegetation on the reduction of road traffic noise levels under varying traffic conditions. Roadside vegetation which have the potential to act as noise barriers were selected for this study. The road traffic noise was measured together with the parameters that control the vegetation. Several noise level descriptors were recorded together with the A-weighted continuous noise level. The results show that higher frequency noise (above 4 kHz) is heavily attenuated by the vegetation barriers with virtually no attenuation for low frequency noise (below 100 Hz). The width of the vegetation barrier is linearly proportional to the amount of sound absorption. Without the vegetation barrier, the observed maximum and minimum noise levels were 72 dB(A) and 64 dB(A) respectively. On average, vegetation barriers were able to reduce the noise by 4 dB(A) which corresponds to an approximately 40% acoustic energy reduction. Thus, with careful planning and growing of roadside vegetation, the effect of road noise can be reduced.
BARIER VEGETASI Vegetation barriers were able to reduce the noise by 4 dB(A) which corresponds to an approximately 58% acoustic energy reduction. The measurements clearly show that higher frequency noise is heavily attenuated by the vegetation barrier and virtually no attenuation of low frequency noise. The noise absorption is linearly proportional to the width of the vegetation barrier. In order to achieve higher absorption of 5 dBA or better, width of the vegetation barrier must be at least 1.5 meters thick. No clear dependency on the height of the vegetation barrier. Data shows that most of the high noise values are in the mid frequency range where 4 dB(A) or above absorption rates due to vegetation barriers were observed. Vegetasi pepohonan rindang untuk meredam kebisingan
NATURAL VEGETATION Natural vegetation, if high enough, wide enough, and dense enough, can decrease roadway traffic noise. Vegetation plant noise barrier are environmental friendly, having natural appearance and often pleasant in visually inspection. The effectiveness in screening depends on the thicknesses of vegetation belts along the roadways and density of leaves (type of vegetation). Effective noise barriers can reduce noise levels by 10 to 15 decibels. However, the degree of difficulty increases with the level of reduction. Proceedings of the Technical Sessions, 25 (2009) 1-6. Institute of Physics – Sri Lanka
Noise absorption for range of frequencies. www.ecy.wa.gov/programs/sea/pubs/93-31/faq.html
Variation of noise absorption with the vegetation barrier width. speclab.cr.usgs.gov/PAPERS.calibration.tutorial/
Noise absorption with vegetation barrier height www.ecy.wa.gov/programs/sea/pubs/93-31/faq.html
62 Road noise with and without vegetation barrier www.ciesin.org/docs/005- 477/005-477.html
63 Mitigation of Traffic Noise “A traffic noise impact occurs when the predicted levels approach or exceed the noise abatement criteria (NAC) or when predicated traffic noise levels substantially exceed the existing noise level, even though the predicted levels may not exceed the NAC.” Federal Rule – Highway Traffic Noise Analysis & Abatement Policy & Guidance FHWA – June 1996 (23 CFR 772)
64 The Use of Vegetation for Noise Reduction The following excerpt from the federal regulation cited above and drawing explain the limitations of using vegetation for noise mitigation: Vegetation Vegetation, if it is high enough, wide enough, and dense enough that it cannot be seen through, can decrease highway traffic noise. A 61 ‐ meter width of dense vegetation can reduce noise by 10 decibels, which cuts in half the loudness of traffic noise. It is usually impossible, however, to plant enough vegetation along a road to achieve such reductions. Source: http://www.healthguidance.org/authors/585/Earl-L.-Butz
JALUR HIJAU JALAN RAYA Roadside vegetation can be planted to create a psychological relief, if not an actual lessening of traffic noise levels. Since a substantial noise reduction cannot be obtained for an extended period of time, the FHWA does not consider the planting of vegetation to be a noise abatement measure. The planting of trees and shrubs provides only psychological benefits and may be provided for visual, privacy, or aesthetic treatment, not noise abatement. Source: http://www.healthguidance.org/authors/585/Earl-L.-Butz
KEBISINGAN LALU-LINTAS Traffic noises produced by trucks, cars, and city buses were recorded on magnetic tape to provide the sound source. These prerecorded sounds were played back through tree and shrub barriers, and the sound level was measured behind the barriers at varying distances. This procedure was repeated at nearby locations, but without the trees, to evaluate the effectiveness of trees in reducing the noise level. Source: http://www.healthguidance.org/authors/585/Earl-L.-Butz www.burnley.gov.uk/site/scripts/documents_inf...
The potential value of vegetation as noise abaters, as determined by the study, was deemed very good. Findings showed that reduction of sound values in the order of 5 to 10 decibels are not unusual for wide belts of tall, dense trees. Species did not appear to differ greatly in their ability to reduce noise levels, provided the deciduous varieties were in full leaf. However, evergreens are favored for year-round noise screening. A supplementary study of various surfaces indicated that, from a noise-reduction standpoint, surfaces covered with trees were the best. www.highways.gov.uk/roads/projects/11064.htm
Screening of urban residential property was effective with a single row of dense shrubs backed by a row of taller trees, totaling a depth of 20 feet. Screening for rural areas or freeways where truck traffic is heavy requires wider belts consisting of several rows of tall trees in dense plantings. Distances of 100 feet or more between the noise source and the area to be protected were found desirable. Source: http://www.healthguidance.org/authors/585/Earl-L.-Butz egov.cityofchicago.org/chicagotrees/forest.html
69 Recommendations arising from the study that may be applied to some current noise problems include: —To reduce noise from high-speed car and truck traffic in rural areas, plant 65- to 100-foot-wide belts of trees and shrubs, with the edge of the belt within 50 to 80 feet of the center of the nearest traffic lane. Center trees should be at least 45 feet tall. Consult local nurserymen and landscape architects for specific varieties at a given locality. —To reduce noise from moderate-speed car traffic in urban areas where the interaction of tires and roadway is the principal cause of noise, plant 20- to 50-foot-wide belts of trees and shrubs, with the edge of the belt from 20 to 50 feet from the center of the nearest traffic lane. Use shrubs 6 to 8 feet tall next to the traffic lane, with backup rows of trees 15 to 30 feet tall. —For best results, trees and shrubs should be planted close to the noise source rather than to the area that needs protection. —Where possible, use taller varieties of trees that have dense foliage and relatively uniform vertical foliage distribution, or combinations of shorter shrubs and taller trees to give this effect. Where the use of tall trees is restricted, use combinations of shorter shrubs and tall grass or similar soft ground cover in preference to paved, crushed rock, or gravel surfaces. —Trees and shrubs should be planted as close together as practical to form a continuous, dense barrier. The spacing should conform to the established local practices for each species. —Where year-round noise screening is desired, evergreens or deciduous varieties that retain their leaves throughout most of the year are recommended. —The planted belt should be approximately twice as long as the distance from the noise source to the receiver. When used as a noise screen parallel to a roadway, it should extend equal distances along the roadway on both sides of the protected area.
Screening is most effective when trees and shrubs are combined with soft rather than hard surfaces, such as pavement or gravel. This can result in a 50 percent or more reduction in the apparent noise. Certain natural and practical considerations limit the use of trees and shrubs as noise screens. Due to the physical nature of sound and the extreme sensitivity of the human ear, sound cannot be brought below the threshold of hearing, no matter how extensive the natural vegetation. Very thinly planted trees, or trees in poor condition as a result of neglect or of an unfavorable growth environment, offer little resistance to the passage of sound. Ground forms are frequently limiting, as when elevated highways are above the treetops so that there is relatively minor sound absorption from below. Also, a right-of-way or land use requirements may prevent an effective noise screening, especially where belts of 75- to 100-foot widths are needed. Source: http://www.healthguidance.org/authors/585/Earl-L.-Butz www.travel-images.com/photo-lord-howe7.html
General requirements for developments that include sensitive receiving environments : Buildings are designed and constructed to reduce the intrusion of noise, by locating rooms most sensitive to noise such as those for sleeping, relaxation or study, furthest from existing and potential noise sources.
Noise Control in the Built Environment The most intensive exploration of new technologies for transportation noise control is in sound barrier. The effective noise barriers can reduce noise levels by 10 to 15 decibels, cutting the loudness of traffic noise in half. This is often true initially. However, a common problem arises when the abatement effect "wears off" over time, leading to renewed community complaints. The noise barriers seldom achieve 10 dB of noise reduction, and typically achieve about one-half that much. The barriers are designed for ground floors only; upper floors receive little or no benefit. The reduction is heard only by the residents closest to the wall. The benefits are variable.
74 Noise Control in the Built Environment Current techniques in use include: Noise and Sound Walls: Built of wood, stucco, concrete, masonry, metal and other materials, these walls have limitations. They must be high enough and long enough to block the view of a road (although not generally higher than 25 feet, for structural and aesthetic reasons); and they often do little for hillside homes above the road. Openings for driveways or intersecting streets will destroy the effectiveness of a sound wall.
75 Noise Control in the Built Environment Earth Berms: Formed from earth mounds and walls (and more attractive than sound walls) earth berms can require considerable land to build, especially when they are high. Freeway Lids: Noise mitigation can be a tremendous secondary benefit of freeway lids. This solution is very expensive, however, and may not compete well with other needs for scarce transportation funding. Low-Noise Pavement: Still in experimental use, low-noise pavement is currently being researched. (A test patch was in place on I-5, between Seattle and Tacoma). Because the pavement has a tendency to break up under heavy use and can lose its special ability over time, its applications may be limited.
ArtCrete screen walls, perimeter fences, buffers and sound barriers. It provides total solutions for your specific sound barrier wall and decorative fencing requirements. It is a multi-source company offering products from worldwide leaders in ornamental pre- cast concrete systems. It offers a full line of products and services from site evaluation, initial design and engineering through installation and customer support. The ArtCrete Collection offers two different systems. LW The light weight, pre-engineered modular wall system that uses interlocking panels and posts made of high performance glass fiber and steel reinforced pre-colored concrete panels and post. HD The heavy duty, customized modular sound and sight wall system that is well suited for "Design-build."
78 Noise Management In addressing land use and development, the location of and relationship between various land uses and the effects of land use and development, including noise management issues, are required to be considered. The qualities of the acoustic environment are conducive to: (a) the wellbeing of the community or a part of the community, including its social and economic amenity; (b) the wellbeing of an individual, including the individual opportunity to have sleep, relaxation and conversation without unreasonable interference from intrusive noise. Manajemen Kebisingan
The policy is to enhance or protect acoustic environmental values of through : (a) incorporating noise levels for the local area; (b) ensuring appropriate acoustic information is obtained at the development assessment stage to assess impacts on the acoustic environmental values. Manajemen Kebisingan
General This policy also seeks to provide clear guidance to those seeking development approval, regarding the assessment provisions for projects which either emit noise or introduce a sensitive receiving environment with the potential to be affected by a noise emitter. Manajemen Kebisingan
Manajement Kebisingan Noise can be defined as unwanted sound that unreasonably intrudes into our daily activities and can cause varying degrees of nuisance and annoyance. Many sources of noise are often associated with urban development including road, air and rail transport, industrial operations, neighbourhood and recreational pursuits, and agricultural activities.
Noise can affect human health and well-being. This can occur in a number of ways, including annoyance reaction, sleep disturbance, interference with communication, performance effects, effects on social behaviour, and hearing loss. If it is allowed to continue it may cause severe mental stress. It can also cause very real physical problems such as chronic exhaustion, high blood pressure and heart disease. Noise that occurs at night is more likely to disturb a community than noise that occurs during the day. Noise may contain annoying characteristics, such as : (a) tonality - humming and whining; (b) modulation - regular changes in level or pitch such as a siren; (c) impulsiveness - hammering. Manajemen Kebisingan
A proposed development should not result in significant deterioration of the existing acoustic environment. The development of a sensitive receiving environment should not occur where existing noise sources would result in the acoustic environment of this new development being unreasonably compromised. Manajemen Kebisingan
Prior to lodging an application for a development an evaluation of the suitability of the proposal is conducted, including a review of the constraints and opportunities for that development. In doing this, at least the following is considered prior to finalising the proposal: (a) location; (b) interaction with the surrounding environment, both internal and external to the development. Manajemen Kebisingan
In particular, the various types of land uses such as nearest noise emitters and/or sensitive receiving environments are identified in the planning process. Prior to making an assessment an initial scoping assessment is considered to determine the background noise levels of the surrounding environment. This assessment should be representative of the operation of existing or proposed noise generating activities. Information from this assessment would be valuable in determining the appropriateness of the development for that location. Manajemen Kebisingan
When considering the likely impact of a proposed development and the times when noise will be emitted or received, it is also important to note whether the noise emissions are likely to contain annoying characteristics. The different types of noise generating activities that need to be considered include : 1.Noise during construction phase; 2.Noise from normal plant operation; 3.Transport and traffic noise, including increased traffic 4.Movements; 5.Behavioural noise; 6.Music and entertainment, both live and recorded; 7.Public address systems; 8.Noises normally associated with the conduct of a 9.Particular industrial or commercial use. Manajemen Kebisingan
87 Other noise generating activities arising from within the development site should also be taken into consideration at the planning phase. For example, locating residential backyards with pools and lounge rooms with sound systems away from bedrooms of neighbouring houses. Developments with mixed uses need to consider noise impacts on residential components or other noise sensitive environments of the development. When considering noise attenuation measures, applicants should evaluate a range of acoustic treatments available to achieve the required noise criteria. Acoustic fencing is the least preferred noise attenuation measure and should only be used where all other measures have been explored, or where necessary to supplement other measures. Manajemen Kebisingan
88 It should be noted that, depending on the issues, officers from different areas within council may need to be involved in the assessment of the noise component of a development application. For example the range of issues for a noise assessment that are likely to require input from different areas within council are - 1.Acoustic performance issues; 2.Wildlife and vegetation issues; 3.Landscaping and safety issues; 4.Amenity issues; 5.Road access; 6.Structural requirements, design and proposal layout issues; 7.Maintenance issues. Manajemen Kebisingan
Noise control strategy : A clear and concise statement is required which sets out the proposed strategy or strategies to deal with each of the identified noise issues. This may include a combination of: a. Source control - such as plant selection; b. Source modification – such as acoustical treatments or management measures; c. Propagation control – such as buffers and barriers; d. Receptor modification – such as a dwelling upgrade. Manajemen Kebisingan
(f) Control at the source: 1.Use of low-noise equipment such as refrigeration condensers, packaged low-noise air compressors or generator sets; 2.Use of alternative, quieter technology, for example replacing sirens with flashing lights, using electric cranes in preference to diesel-powered cranes and using mobile phones or personal pagers instead of telephone extension bells; 3.Use of more appropriate control technologies such as variable speed drives on cooling tower fans or two-speed fans on air-cooled condensers in order to avoid stop/start operations and to reduce noise emission levels at night; 4.Use of carbon monoxide monitors to control fan operations in carpark exhaust systems, again matching fan performance to demand to effectively reduce noise emissions at night; 5.Use of solid-state switching in preference to relays; 6.Use of soft-start electric motors on drives which require cyclic operation; 7.The report describes any recommended or proposed low-noise plant. Where the make and model of specific plant selections can be identified, their noise performance is detailed in terms of their sound power levels or sound pressure levels at nominated distances. Where schematic or conceptual designs only are available, the typical performance and improvements are stated; Manajemen Kebisingan
(g) Source modification: This may include technical treatments such as acoustical enclosures around plant, or may rely on staff implementing appropriate procedures to minimise noise: 1.There are a number of firms specialising in noise control, offering both off the shelf and purpose- designed acoustical treatments. Such treatments have the potential to interfere with the performance and/or efficiency of plant operation. It is therefore recommended that specialist advice be sought in the planning and design of these measures; 2.The report describes the intended noise reduction measures and their anticipated performance; 3.Management measures include all noise control actions which rely on people to behave in a particular way. This may require delivery drivers to use a specific route or curtail particular activities such as the use of exhaust brakes. It may require staff to restrict certain activities to certain times or to intervene by closing doors or re-directing activities; 4.If management measures are proposed, a site-specific noise management plan is required. This plan should include at least one contingency action in the event that the primary noise plan fails to achieve or maintain the nominated outcome; Manajemen Kebisingan
Propagation control includes the use of buffer zones and/or noise barriers to achieve noise attenuation. The report shall include plans showing the locations and heights of all noise sources, and the locations and heights of any proposed noise barriers. Where buildings are relied on to provide barrier screening, the elevations and locations of openings such as doors and windows are also provided. Manajemen Kebisingan
93 (i) Information on noise monitoring and/or noise predictions, modelling and results including: (1) A description of the existing noise climate including : a.Ambient noise levels during day, evening and night b.Periods on both weekdays and weekends; c.Prevailing atmospheric conditions. (2)Location of monitoring sites and rationale for its Selection; (3)Noise prediction results for when attenuation measures are provided and where no attenuation measures are provided; (4)Details and assumptions used in the model for predictions; (5)Criteria established for assessment purposes. Manajemen Kebisingan
94 When including details of attenuation measures identified to achieve compliance with noise criteria, also provide the methods used to calculate this attenuation. For development of sensitive receiving environments adjacent to roads and railways, as identified in the Road and Rail Noise Overlay : (a) Describe the noise attenuation measures to be implemented to reduce traffic noise affecting the proposed adjoining development. Noise nuisance should be ameliorated in the first instance through the design, orientation and layout of the site. As stated earlier, to achieve the design level noise criteria it should be demonstrated that a range of acoustic treatments available for application at the site were evaluated. Manajemen Kebisingan
95 Design and layout for rooms sensitive to noise
96 Noise Management For developments including a sensitive receiving environment adjacent to roads and railways, the noise report should also include a suitably scaled plan indicating the following : (i) for road noise : a. predicted 60 (or 63) dB(A) LA10 (18 hour or less) contour with and without noise attenuation measures; b. predicted 55 dB(A) LAeq (1hr) contour with and without noise attenuation measures; c. the noise contours are plotted for both lowset and two- storey dwellings. For dwellings, the receptor height is taken to be 1.5 metres above each finished floor level.
97 Noise Management For developments including a sensitive receiving environment adjacent to roads and railways, the noise report should also include a suitably scaled plan indicating the following : (ii) for rail noise : a. predicted 87dBA LA max contour with and without noise attenuation measures; b. predicted 65 dB(A) LAeq (24 hour) contour with and without noise attenuation measures; c. predicted 55 dB(A) LAeq (1hr) contour with and without noise attenuation measures; d. the noise contours are plotted for both lowset and two- storey dwellings. For dwellings the receptor height is taken to be 1.5 metres above each finished floor level.
98 Noise Management (iii) location of proposed barriers indicating heights of barriers and portion of land required to accommodate mounds, where applicable; (iv) floor plan / layout of proposed development, where applicable; (v) the noise measurement location and its rationale for selection; (vi) calculations must indicate the attenuation provided by each alternative through distance, barrier, building and angle of exposure; (vii) show cross sections of the design and proposed location of the acoustic barriers where not in compliance with the policy; (viii) the option for the use of acoustic barriers is supported by an assessment of the public safety and visual amenity of the structures; (ix) provide indicative elevations of cross sections and plans to indicate that the barriers will fit on the site and that adequate park dedication is provided to fit the barrier.
General requirements for developments that include sensitive receiving environments : 1.Buildings are designed and constructed to reduce the intrusion of noise, by locating rooms most sensitive to noise such as those for sleeping, relaxation or study, furthest from existing and potential noise sources. 2.Buildings are constructed using materials including insulation and glazing materials with a high noise transmission loss. 3.Reduce the area covered by openings such as windows and doors that face existing and potential noise sources. 4.Provide mechanical ventilation to rooms most sensitive to noise such as those for sleeping, relaxation or study. Manajemen Kebisingan
100 Noise Management General requirements for developments that include sensitive receiving environments : Provide adequate setback or buffer distances between noise sources and the sensitive receiving environment : (i) in providing setback or buffer distances between noise sources and sensitive receiving environments, site specific distances are calculated by a suitably qualified acoustic consultant. Issues including topography, climate and all current and predicted impacts from incompatible adjacent land uses, during day and night time periods, are considered in determining these buffer distances; (ii) where buffer distances are incorporated within the lot or premises, sensitive receiving environments are indicated on proposal plans and are not located within the buffer.
101 Noise Management General requirements for developments that include sensitive receiving environments : (f) Design, orientate and construct buildings to effectively screen external private open space areas from the noise source. (g) Use appropriate buffer distances between the noise source and external private open space areas. (h) Provide suitable noise attenuation barriers where needed. (i) Where requested, also provide noise monitoring information and/or noise prediction and modelling including noise assessment results, as previously outlined.
102 Noise Reduction Details are provided about the proposed noise control measures to be applied at the site, including the expected noise reduction where the earlier assessment of predicted levels shows adverse local and remote noise impact. The scale of the improvements to be provided by the noise control measures is predicted to confirm compliance with the appropriate criteria. For example, this could be demonstrated by providing contour predictions on a site plan for each of the attenuation options. If acceptable noise levels cannot be achieved, additional information is provided to justify approval of the development.
103 Noise Attenuation Barriers The use of barriers for noise attenuation is the least preferred option, however, the following should be considered during the design of the development where noise attenuation measures in the form of barriers, fences and vegetated buffers are required. The design of these noise attenuation measures should not: (a) compromise the ability to protect property from crime and vandalism; (b) obstruct or reduce passage by pedestrians to public transport nor contribute to deterioration of accessibility to public transport; (c) create sterile areas that are unusable, unsafe and negatively affect the streetscape; (d) result in continuous barrier fencing along roadways which has both visual impacts and also impacts on people and wildlife movement; (e) obstruct the overland flow of stormwater or cause increased flooding or ponding of stormwater;
104 Noise Attenuation Barriers Noise attenuation measures for dwellings or building should be designed as architectural features including the stepping of buildings, angling wall alignments, and roof line variation to add interest to the form and enhance the appearance to the street frontage. Noise attenuation measures are designed to facilitate wildlife movement while maintaining noise attenuation effectiveness by ensuring: (a) vegetated earth mounds are considered in preference to fences or barriers; (b) suitable vegetation is provided adjacent to noise attenuation mounds, barriers and fences to facilitate wildlife movement; (c) attenuation barriers and fencing incorporate wildlife movement measures that are suitable to the species expected to use the area; (d) vegetation species selected are locally native species.
Noise Attenuation Barriers Continuous barrier fencing is avoided along trunk collector and sub-arterial roads so as to not create sterile traffic corridors. Views are retained where possible by using appropriate buffer distances, height, orientation and materials. Where fencing is used it is articulated, landscaped and incorporates multiple access points for pedestrians and cyclists. Acoustic fencing is of low maintenance design. When using measures such as earth mounds, fences or a combination of these.
106 Noise Attenuation Barriers It should be noted that a covenant may also be applied where an acoustic barrier is required to be maintained on land to protect the amenity of the greater neighbourhood for example an acoustic fence which runs along the boundary of several individual properties. As stated earlier, it should be demonstrated that other attenuation measures have been considered first as alternatives to structural barriers. For example, at the design phase of a development, consideration should be given to the use of land between the source and receiver which can increase buffers and assist in attenuation. Such land uses could be minor roads and/or parks.
107 Methods to Minimise Impacts from Noise Emissions (1) This is not an exclusive list but merely provides a range of examples for minimising noise emission impacts. (2) Siting and design - (a) Select an appropriate site for the use considering the proximity to sensitive receiving environments and the local meteorological conditions; (b) Design site layout to ensure building openings, roads, parking areas and other major activities and operational areas are located away from current or future sensitive receiving environments; (c) Where possible use the layout of the buildings, site infrastructure and natural topography as noise barriers; (d) Where possible confine noisy processes to areas protected by enclosures or barriers; (e) Locate noisy processes such as loading bays and entrances/exits away from sensitive receiving environments; (f) Locate noise sources such as air compressors, pumps and similar in areas furthest from sensitive receiving environments, provide effective noise barriers or enclosures, and keep doors on enclosures closed when operating.
108 Methods to Minimise Impacts from Noise Emissions (3) Construction standards - (a) Vehicle traffic areas are paved, have low gradients and are maintained in good condition; (b) Install double-glazing to windows and sound locks to doors facing sensitive receiving environments; (c) Buildings housing noisy operations, activities or equipment are constructed of suitable materials to reduce noise transmission such as ceilings and walls lined with sound absorbing material; (d) Reduce structure-borne noise and vibration by mounting equipment on appropriate isolation systems designed by a specialist in this field.
109 Methods to Minimise Impacts from Noise Emissions (4) Operation standards - (a) Install noise suppression devices to equipment according to the manufacturerâ€™s specifications and ensure the efficiency of these devices is maintained; (b) Design and maintain adequate noise buffers between noise sources and sensitive receiving environments. In particular, install noise barriers such as screens around noisy equipment, operations and activities; (c) Fit all diesel engines and noisy vehicles with efficient exhaust mufflers; (d) Avoid installing machinery that may have humming or whirring components or impulses, or annoying tonal or hammering noises. If such machinery is installed, noise suppression devices are applied to mitigate potential nuisance; (e) Fit effective inlet and exhaust silencers to air compressors and ensure that air pressure operated controls and air operated valves on silos and hoppers are equipped with silencers; (f) Where possible, substitute equipment with an equivalent quieter/lower sound power level piece of equipment, for example, electric rather than diesel or air powered; (g) Where possible replace alarms, horns and telephone bells with visual signs, mobile phones or pagers; (h) Where blasting of rock or hard ground is involved, use technologies that minimise airblast overpressure and ground vibration.
110 Methods to Minimise Impacts from Noise Emissions (5) Noise management measures - (a) Ensure that openings including windows and roller-doors facing sensitive receiving environments are kept closed and all unnecessary openings are sealed. Install signage to alert staff and/or visitors to their responsibilities to minimise the generation and propagation of unnecessary noise; (b) Limit noisy routine operations to standard working hours of 7am to 6pm Monday to Friday, and 7am to 1pm Saturday. Noisy work should not be carried out on Sundays or public holidays, except where approved as part of the land use or another approval such as an activity under the Environmental Protection Act 1994; (c) Conduct noisy activities at times when the likelihood for nuisance is minimised, for example, the middle of the day; (d) Work outside of standard working hours is limited to quiet â€œfinishing offâ€ work and generally conducted within buildings; (e) Limit vehicle movements, especially deliveries and truck movements, to standard working hours;
111 Methods to Minimise Impacts from Noise Emissions (5) Noise management measures - (f) Where possible, activities such as concrete pours are restricted to standard working hours. If activities are required to occur outside of these hours, affected premises are notified of the duration and times in advance of the event; (g) Employ regular inspection and maintenance programs to ensure noise control fittings such as seals, doors and exhaust systems are in good working order and prompt attention is given to loose or rattling covers, worn bearings and broken equipment; (h) Develop and implement an Environmental Management Plan including procedures for - (i) noise management; (ii) pollution prevention; (iii) staff training; (iv) customer education where applicable; (v) definition of roles and responsibilities; (vi) monitoring of performance; (vii) contingency actions.
Earth Mounding - Landscape and Barrier Fencing
115 Specifications for Noise Attenuation Measures (Barriers, fences and mounds) Type of Measure Specifications Earth Mounding - Landscaped 1.Area required from property boundary to pavement kerb is a minimum of 11.6 metres - buffer zone plus road reserve/ verge. 2.Mound set at 3.6 metres from back of kerb. 3.Standard street tree planting to apply in 3.6 metre zone. 4.Mound width at base equal to 8 metres. 5.Maximum mound height at apex ranges from 1 metre to 2 metres. 6.Mound batters do not exceed 1:2 (V:H) slope. 7.Earth mound is clean, compacted fill with topsoil capping to minimum 300mm depth and minimum 100mm mulch layer over mound. 8.Mound is planted with a mixed range of local native species including large shrub/ small tree species and an under-storey of small shrub and groundcover species. 9.Mature height of - 1. large shrub/ small trees is 6 metres; 2. under-storey shrubs is 1 metre. 10.Density of planting is one plant per square metre with ratio one large shrub/ small tree to six under-storey shrubs. 11.All mounding is designed to avoid localised ponding with run-off directed towards suitable areas.
116 Specifications for Noise Attenuation Measures (Barriers, fences and mounds) Type of Meas ure Specifications Earth Moun ding - Land scap e and Barri er Fenci ng Minimum area required from property boundary to back of kerb is 7.6 metres - buffer zone and road reserve / verge. Minimum mound set at 3.6 metres from back of kerb / road edge. Standard street tree planting to apply in 3.6 metre zone. Mound width at base equal to 8 metres with 4 metres to extend within property boundary2. 2 Mound height at apex ranges from 1 metre to 2 metres maximum. Mound batters do not exceed a 1:2 slope (V:H) slope. Earth mound is clean, compacted fill with topsoil capping to minimum 300mm depth and minimum 100mm mulch layer over mound. Mound is planted with a mixed range of local native species including large shrub/ small tree species and an under-storey of small shrub species and groundcover species. Mature height of - large shrub/ small trees of 6 metres; under-storey shrubs of 1 metre. Planting density is one per square metre with a ratio of one large shrub/ small tree to six under-storey shrubs. Fence is of timber materials or other approved materials with height between 1.2 metres to 2 metres. All mounding is designed to avoid localised ponding with run-off directed towards suitable areas.
117 Specifications for Noise Attenuation Measures (Barriers, fences and mounds) Type of Measure Specifications Fence and Planted Buffer Area required from property boundary to back of kerb is a minimum 5.5 metres - buffer zone and road reserve / verge. Dedicated land for planting buffer is a minimum of 2 metres wide. Standard street tree planting to apply in 3.6 metre zone. Planted buffer is clean, cultivated top soil to minimum 300mm depth with minimum 100mm mulch layer over ground. Irrigation system satisfies the local governmentâ€™s standard specifications. Buffer is planted with a mixed range of locally native species including large shrub/ small tree species and an under- storey of small shrub and groundcover species. Mature height of - large shrub / small trees is 4 metres; under-storey shrubs is 1 metre. Planting density is one plant per square metre with a ratio of one large shrub / small tree to eight under-storey shrubs. Fence is of timber construction or other approved fencing products with a maximum height of 2 metres. Fence colour enhances visual amenity.