16/10/2013 1 Kebisingan Industri Penyebab kehilangan/gangguan pendengaran adalah: Kebisingan industri Luka pada telinga akibat ledakan, shock pukulan pada kepala dan benda asing atau infeksi pada telinga. Inside NOISE What is noise? – Definition, energy conducted and sensed, properties: intensity/pressure, frequency, exposure, Why unwanted? – Health Effect, age, psychological: annoyed, concentration, Health Effect, age, psychological: annoyed, concentration, rest/relax problem, communication annoyance, physiological: blood, heart, hearing loss, nausea, muscle control, acoustic trauma (permanent) vs temporary, Who are susceptible? – Esp. Industrial workers, determining factors: sensitivity, age, How to evaluate & control? What is noise? Definisi: Suara-suara yang tidak dikehendaki (for Who? Why?) Suara: sensasi yang diterima telinga sebagai akibat fluktuasi tekanan udara terhadap tekanan d t bil udara yang stabil. Telinga akan merespons fluktuasi-fluktuasi kecil tersebut dengan sensitivitas yang sangat besar. Bising juga diartikan vibrasi/energy yang dikonduksikan dalam media udara, cairan, padatan, tidak tampak dan dapat memasuki telinga serta menimbulkan sensasi pada alat dengar Properties of noise? Properties of noise? Jenis Bising Tergantung pada durasi dan frekuensi Steady wide band noise, bising yang meliputi suatu jelajah frekuensi yang lebar (bising dalam ruang mesin) Steady narrow band noise, bising dari sebagian besar energi bunyi yang terpusat pada beberapa frekuensi saja, h ji b d contoh gergaji bundar. Impact noise, kejutan singkat berulang, contoh riveting Intermitten noise, bising terputus, contoh lalu lintas pesawat
rest/relax problem, communication annoyance, physiological: blood, heart, hearing loss, nausea, muscle control, acoustic trauma (permanent) vs temporary,
Who are susceptible? – Esp. Industrial workers, determining factors: sensitivity,
age,
How to evaluate & control?
What is noise?
Definisi: Suara-suara yang tidak dikehendaki (for Who?
Why?) Suara: sensasi yang diterima telinga sebagai
akibat fluktuasi tekanan udara terhadap tekanan d t biludara yang stabil.
Telinga akan merespons fluktuasi-fluktuasi kecil tersebut dengan sensitivitas yang sangat besar.
Bising juga diartikan vibrasi/energy yang dikonduksikan dalam media udara, cairan, padatan, tidak tampak dan dapat memasuki telinga serta menimbulkan sensasi pada alat dengar
Properties of noise?Properties of noise?
Jenis Bising
Tergantung pada durasi dan frekuensi
Steady wide band noise, bising yang meliputi suatu jelajah frekuensi yang lebar (bising dalam ruang mesin)
Steady narrow band noise, bising dari sebagian besar energi bunyi yang terpusat pada beberapa frekuensi saja,
Intermitten noise, bising terputus, contoh lalu lintas pesawat
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Karakteristik bising
1. Intensitas/tekanan (sound pressure/intensity)
2. Frekuensi3. Durasi eksposur terhadap bisingKetiga karakteristik diperlukan karena:g p Semakin keras suara, semakin tinggi
intensitasnya Frekuensi tinggi lebih berbahaya terhadap
kemampuan dengar. Telinga manusia lebih sensitif terhadap frekuensi tinggi
Semakin lama durasi eksposur semakin besar kerusakan pada mekanisme pendengaran
Contoh…
Intensitas
Laju aliran energi tiap satuan luas yang dinyatakan dalam desibell (dB) – Alexander Graham Bell-
dB adalah merupakan satuan yang dihasilkan dari perhitungan yang membandingkan suatu tekanan suara yang terukur terhadap suatu tekanan acuan (sebesar 0,0002 dyne/cm2).
B = log (int.terukur/int.acuan) untuk mendapatkan angka yang lebih akurat ditentukan dengan angka kelipatan 10 (desi)
karena intensitas sebanding dengan kuadrat tekanan bunyi.
Tekanan = Sound Pressure
Manusia dapar mendengar suara pada tekanan antara 0,0002 dynes/cm2 (ambang dengar/threshold of hearing) sampai 2000 dynes/cm2 range besar sehingga satuan yang dipakai dB (decibel): logaritmik
Dinyatakan dalam decibel (dB) yang Dinyatakan dalam decibel (dB) yang dilengkapi skala A, B, dan C sesuai dengan berbagai kegunaan
Skala A digunakan karena merupakan response yang paling cocok dengan telinga manusia (peka terhadap frekuensi tinggi)
Skala B dan C untuk evaluasi kebisingan mesin, dan cocok untuk kebisingan frekuensi rendah
Ruang kelas: ?dB
Rumah
Restauran
Berbisik
Berteriak
Jet plane
The decibel
SOUND INTENSITY
SOUND SOURCE LINEAR UNITSBel
LOGARITHMIC UNITSDecibel
Lowest limit of hearing 1 0 0
Rustling leaf 10 1 10
Quiet farm setting 100 2 20
Whisper (5 feet) 1,000 3 30
Dripping faucet, quite office 10,000 4 40
Low conversation, residence 100,000 5 50
Ordinary conversation 1,000,000 6 60
Idling car 10,000,000 7 70
Silenced compressor, very noisy restaurant 100,000,000 8 80
Backhoe 1,000,000,000 9 90
Unsilenced compressor 10,000,000,000 10 100
Rock dril, woodworking 100,000,000,000 11 110
Pile driver* 1,000,000,000,000 12 120
Rivet gun* 10,000,000,000,000 13 130
Explosive-actuated tool*, jet plane 100,000,000,000,000 14 140*Intermittent or "impulse" sound
Source: Construction Safety Association of Ontario, Hearing Protection for the Construction Industry, 1985, page 3
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The decibel
dB = 10 log10 (I1/I0) I = Intensitas
dB = 20 log10 (P1/P0) P= Tekanan = 0,0002
dynes/cm2
SP (microbar) SPL (dB) Ratio Intensitas
0,0002 0 100
0,002 20 102
Jadi bila SP berubah 10x, maka dB bertambah ? x
PressurePa Bel (B) Decibel (dB)
Threshold of hearing 0,00002 0 0Quiet office 0,002 4 40Ringing alarm clock at 1 m 0 2 8 80
Sound intensities
Ringing alarm clock at 1 m 0,2 8 80Ship's engine room 20 12 120Turbo jet engine 2000 16 160
Pneumatic chip hammer
103-113 Crane 90-96
Jackhammer 102-111 Hammer 87-95
Concrete joint 99 102 Gradeall 87 94
jcutter
99-102 Gradeall 87-94
Skilsaw 88-102Front-end loader
86-94
Stud welder 101 Backhoe 84-93
Bulldozer 93-96Garbage disposal (at 3 ft.)
80
Earth Tamper 90-96Vacuum cleaner
70
Satuan (Konversi)
1bar=105Pa=105N/m2
=105.105dyne/104cm2
=106dyne/cm2 atau
/ 21microbar = 1 dyne/cm2
Sumber > 1…..
dB=L=20 log(P1/P2)=10 log(P1/P2)2
L/10= log(P1/P2)2
10L/10= 10log(P1/P2)^2=(P1/P2)2
L=10 log(P1/P2)2
=10 log 10L/10 (satu sumber)
=10 log (Σ10Li/10)
L =10 log (10L1/10+ 10L2/10+…)
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Sumber > 1….. (Contoh)
=10 log (Σ10Li/10) (banyak sumber)
=10 log (10L1/10+10L2/10+…)
Perbedaan antara sumber
bunyi
ΣdBA yang turun ditambah ke
bunyi terbesar
0 3,0
1 2,6
2 2,1
3 1,83 1,8
4 1,5
5 1,2
6 1,0
7 0,8
8 0,6
10 0,4
12 0,3
14 0,2
16 0,1
Kebisingan dari 2 sumber
3
2,5
2mba
hkan
pad
a n
lebi
h tin
ggi
Perbedaan (dB)
Tambah pada yg lebih tinggi
0 atau 1 3
2 atau 3 2
4 9 1
14Perbedaan antara 2 tingkat bising, dB(A)
12108642
0,5
1,5
2
1
Dec
ibel
yan
g di
tam
tingk
at k
ebis
inga 4 – 9 1
10+ 0
Frekuensi
Adalah jumlah getaran dalam tekanan suara per satuan waktu (Hertz atau cycle per detik), frekuensi dipengaruhi ukuran, bentuk dan pergerakan sumber, p g ,pendengaran normal orang dewasa dapat menangkap bunyi dengan frekuensi 20-15.000 Hz.
Frekuensi
Dibagi dalam 8 octaf (octave bands), 37.5, 75, 150, 300, 600, 1200, 2400, 4800, 9600 Hz
Telinga manusia bereaksi beda terhadap berbagai frekuensi
Kebisingan ‘rata-rata’ mencakup seluruh Kebisingan rata-rata mencakup seluruh taraf kebisingan dari setiap frekuensi dihitung LeqLeq = ekuivalen noise level/ekuivalen energi levelLeq = 10 log10 (Σ 10 Lpi/10)
Why unwanted?
Health Effect, age, psychological: annoyed, concentration, rest/relax problem, communication annoyance, physiological: blood, heart, hearing loss,
l t l ti tnausea, muscle control, acoustic trauma (permanent) vs temporary,
Efek bising pada manusia
Psikologis, terkejut, mengganggu dan memutuskan konsentrasi, tidur dan saat istirahat
Fisiologis, seperti menaikkan tekanan darah dan detak jantung, mengurangi ketajaman pendengaran, sakit telinga, mual, kendali otot terganggu, dll.
Gangguan komunikasi yang mempengaruhi kenyamanan kerja dan keselamatan.
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Interference with communication by speech
When background or ambient noise levels are sufficiently high enough, the background noise can mask the sound levels of speech that wish to be heard.
Restaurants can often be classic examples of excessive noise interference due to lack of sufficient quality or quantity
f d b bi t i l th t t i iof sound absorbing materials that prevent excessive noise buildup.
Diners have to speak louder and louder to be heard and in doing so compete with one another, thereby increasing the sound levels to even greater levels. Appropriate acoustical treatment will prevent the reflected noise buildup and significantly reduce the necessity for diners to speak louder to enjoy conversations with one another.
Mechanics of hearing
Mekanisme pendengaran
Terdiri dari 3 bagian: telinga luar (daun telinga sampai membran timpani) meneruskan gelombang ke telinga tengah
Telinga tengah: membran timpani (yang melekat pada 3 tulang kecil sampai membrana ovale) getaran diteruskan
Telinga dalam: tube berspiral seperti rumah siput berisi cairan cairan bervibrasi stimulasi rambut sel impuls syaraf otak
Mekanisme pendengaran
Pemaparan pada suara tinggi dan periode/durasi yang lama akan menyebabkan sel syaraf pendengar dan rambut pada corti over aktif sehingga p ggmenimbulkan kehilangan pendengaran permanen
Pengukuran efek bising
Untuk mengevaluasi akibat pemaparan terhadap kehilangan pendengaran, kenyamanan, interferensi komunikasi dan y ,mengumpulkan informasi untuk pengontrolan.
Audiometric test
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Audiometric test
Standard OSHA
Current OSHA Standards•1926.52 Occupational Noise Exposure
•TABLE D-2 - PERMISSIBLE NOISE EXPOSURES
Duration per day, hoursSound Level dBA slow
response
8 908 90
6 92
4 95
3 97
2 100
1 1/2 102
1 105
1/2 110
1/4 or less 115
NAB Kebisingan di lingkungan kerja
USA (TLV ACGHI)t (eksposur) jam dB(A)
8 906 924 95
t dBA8 854 882 91
INDONESIA Permen 51/1999
3 972 100
1,5 1021 105
0,5 110<0,25 115
kebisingan impulsif < 140 dB
1 9430 mnt 9715 mnt 1007,5 mnt 103
3,75 mnt 1061,88 mnt 109
dstdilarang > 140 dB
How Does Excessive Noise Damage Your Ears? Microscopic hair cells of the cochlea are exposed to
intense noise over time Hair cells become fatigued and less responsive, losing
their ability to recover. Damage becomes permanent resulting in noise-induced
permanent threshold shift. Risk of Hearing Loss g Estimated Risk of Incurring Material Hearing Impairment
as a Function of Average Daily Noise Exposure Over a 40-year Working Lifetime (source: NIOSH)
Average Exposure 90 dBA 29% Average Exposure 85 dBA 15% Average Exposure 80 dBA 3%
Ketulian
= berkurangnya ketajaman pendengarandibanding/terhadap orang normal (15 dB)/ gol usia
• Ada 2 macam: - permanen: karena penyakit, usia tua, obat, trauma, dankebisingan- temporer: akibat ekposur bising, dapat pulih setelahp p g, p pistirahat beberapa saat tergantung keparahan
• Ketulian temporer akan menjadi permanen bila terusterekpos bising (dari rumah, tempat umum, rekreasi, musik, industri, dll.)
• Secara mekanisme: ketulian ada 2:- konduktif: peralatan konduksi suara rusak akibattrauma atau sakit- sensorinueral: akibat persyarafan pendengaran rusak
What Is The Purpose of Having a Hearing Test on a Regular Basis?
An audiometric testing program is used to track your ability to hear over time. – Baseline and annual
T t d id th l d t th t b Test records provide the only data that can be used to determine whether the program is preventing noise-induced permanent threshold shifts. It is an integral part of the hearing conservation program.
Case Study 1. Teenage Girl From the American Academy of Family Physicians website, Rabinowitz article
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FIGURE 1. Audiogram findings in the patient in case 1.
The area below the curves represents sound levels that the patient could still hear. (X = left ear; O = right ear)
Case Study 1 Conclusion
"Temporary threshold shift" example
Common in persons exposed to high noise
Represents transient hair cell pdysfunction
Complete recovery can occur
Repeated episodes of such shifts causes permanent threshold shifts because hair cells in the cochlea are progressively lost.
Case Study 2 Factory Worker Age 55 Case Study 2 Conclusion
Noise Induced Hearing Loss – Speech discrimination and social function
interference – Difficulty in perceiving and differentiating consonant
sounds – Sounds such as a baby crying or a distant telephone y y g p
ringing, may not be heard at all.
Tinnitus – Common symptom of noise overexposure – Further interferes with hearing acuity, sleep and
concentration.
These impairments have been associated with depression and an increased risk of accidents.
Carpenter Hearing Losses by Age Pengukuran kebisingan
• Mengukur overall level sound level meter (satuan dBA)
• Mengukur kebisingan pada setiap level frekuensi SLM dengan frequencyfrekuensi SLM dengan frequency analyzer
Sound level meter dengan octave band analyzer, mengukur level bising pada berbagai batas oktaf di atas range pendengaran manusia dengan mempergunakan filter menurut oktaf yang diinginkan (narrow band analyzers untuk spektrum sempit 2-200 Hz)
NOISE KALIBRATOR
NOISE MEASUREMENT KIT
SOUND LEVEL METER
NOISE DOSIMETER
PENGUKURAN PADA PEKERJA
DOSEBADGER
Damage risk criteria
Variation in individual susceptibility The total energy of the sound The frequency distribution of the soundOther characteristics of the noise
h h th it iexposure, such as whether it is continuous, intermittent, or made up of a series of impacts
The total daily time of exposure The length of employment in the noise
environment.
Noise control
A source radiating sound energy
A path along which the sound energy travels
A receiver such as the human earA receiver such as the human ear
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Pengendalian kebisingan
SUMBER PATHWAY/MEDIA PENERIMA/RECEIVER
Pengendalian dilakukan di 3 bagian: SUMBER, RUANG ANTARA sumber dan penerima/pekerja, padaPENERIMA/PEKERJA
Urutan pengendalian paling efektif:
• Kurangi/hilangkan sumber bising
• Pengendalian pathway: jarak diperjauh denganperisai/isolator/automatisasi
• Perlindungan penerima dari bising (APD)
•Cara teknis:
APDPerpanjang jarak
Reduksi waktuPerisaiInsulasi sumber
Isolasi pekerjaAbsorpsi/dampingSubstitusi
PENERIMAPATHWAYSUMBER
•Cara medis:Cara medis:Pemeriksaan ketajaman pendengaran secara periodikPenempatan pekerja sesuai dengan kepekaan thd bisingMonitor ketulian temporer
•Cara manajemen:Reduksi waktu eksposurDiklat pemakaian dan pemeliharaan APD
Noise control
Source: modification or redesigning of the source.– The modification of compressed air jets for parts
ejection, to reduce noise by altering the jet flow.
M lti l i i j ti l l i th– Multiple-opening air ejection nozzel: less noise than
single-opening.
Noise control
Noise can be controlled at the source, along the path or at the worker. At the source, equipment may be replaced by quieter models, or less noisy work procedures can be adopted. In general, less friction and vibration mean less noise Maintenance procedures such asnoise. Maintenance procedures such as lubrication may sometimes reduce noise by reducing friction. Equipment can sometimes be modified to reduce the amount of noise that is generated. Sound-absorbing material may be attached to the noise source. Or the frequency of the noise may be shifted to one that is less hazardous.
Noise control
Noise can often be controlled along the path to the worker with the use of sound-absorbing paneling on walls or ceilings, and enclosures around noisy machinery.
Controls at the worker include both d i i t ti t l d ladministrative controls and personal
protective equipment. – Administrative controls modify how the work
is carried out. – The time employees spend in noisy areas
may be reduced. – Workers in noisy areas may be rotated to
less noisy areas. As the distance from the noise source increases, the pressure (or intensity) of the noise decreases faster than its sound level.
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Noise control
Noisy operations may be conducted outside normal working hours to reduce the number of people exposed. people exposed.
Where noise exposures cannot be reduced by other methods, hearing protection is required. This includes ear plugs and ear muffs.
Insulation of the workers
A separate noise insulated room provides effective control (up to 30 dB noise reduction).
Machine insulation
Machine: on floors and walls vibrate themsound radiation
proper use of machine mountings insulates the machine and reduceinsulates the machine and reduce the transmission of vibration
Control of noise by absorption
Travels out in all direction
When encounter wallsreflected
Total noise exposure within the room = direct + reflected noiseroom = direct + reflected noise
Application of sound absorption material (However, limited: no effect on direct noise).
Reduction of exposure time
Limiting the total daily exposure reduces the noise hazard.
See TLV
Personal protection against noise
Many operations cannot be quieted by engineering methods.
Degree of discomfort employee education is adequate
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Faktor-faktor yang mempengaruhi bising
Tipe bising: menerus dan terputus
Lokasi pekerja
Waktu kerja
Steps aiming to control noise at work Assess risks to develop a noise control
plan Reduce risks for all employees Investigate and implement good practice
for control of noise for control of noise Prioritise noise control measures Use hearing protection for residual risks Carry out a noise dosimetry program to
check the effectiveness of noise control measures
Some simple noise control techniques Application of damping material to
chutes, hoppers, machine guards etc., can give a 5-25 dB reduction in the noise radiated
Cabin internal noise can be reduced by 10-12 dB by applying damping pads and sound barrier mats to floor and engine bulkhead
Reduce fan speed by 30% to achieve a noise reduction of 8 dB
BARRIER-BARIER ATAU PANEL
ISOLASI PEKERJA/MESIN DI TEMPAT BISING
BAHAN ABSORBER BAHAN BARRIER
Noise control can be complex
Engage employees in process
Use noise control consultants to help solve your problems if complex
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Hearing protectors
Selected for protection, user preference and work activity
Guard against over-protection — isolation can lead to under-use and safety risks
Require information, instruction, training, supervision and motivation
Will only protect if worn all the time and properly
Rating hearing protectors
The sound level conversion (SLC80 ) rating of a
hearing protector, ear plugs or headset is a simple
number and class rating that is derived from a test
procedure as outlined in the Australian/New Zealandprocedure as outlined in the Australian/New Zealand
Standard AS/NZS 1270:2002
Class and specification of hearing protectors
SLC80 Class May be used up to this noise exposure level
10 to 13 1 90 dB(A)
14 t 17 2 95 dB(A)14 to 17 2 95 dB(A)
18 to 21 3 100 dB(A)
22 to 25 4 105 dB(A)
26 or greater
5 110 dB(A)
Ear plugs
Properly fitted Wrongly fitted
Ear muffs
Proper clamping force Worn-out head band
Reduction in protection provided by hearing protectors with decreased wearing time
Example: Effectiveness of
earing an ear
Wear timeEffective
attenuation
60 minutes 30 dB
wearing an ear muff with a rating of 30 dB for an exposure time of one hour
55 minutes 11 dB
50 minutes 8 dB
45 minutes 6 dB
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Our challenge
Away from … Noise assessment as the end point Reliance on hearing protectionTowards … Control of noise risks through prioritised
action plans Introducing equipment with good noise
and vibration characteristics – ‘Buy Quiet’
Example….
Durasi tingkat bising yang diijinkan dapat dilihat dari tabel di bawah ini:
Kebisingan yang terukur di suatu area adalah 90 dB selama 2 jam sehari, 97 dB
Durasi per hari
Tingkat bising
86
9092j ,
selama 2 jam, dan sisa 4 jam berikutnya terdapat variasi tingkat bising secara bergantian 95 dB selama 10 menit dan 80 dB selama 10 menit.
Tentukan apakah tingkat kebisingan yang terukur masih dalam batas yang diijinkan atau tidak.
432
1,51¾½¼
9597100102105107110115
TWA untuk kebisingan: berdasarkan standar kebisingan.
Jumlah jam dB(A)
1,5 102
1,0 105
0,75 107
0,5 110
Jumlah jam dB(A)
8 90
6 92
4 95
3 97
STANDAR KEBISINGAN
0,25 1152 100
dB(A) 80 90 95 97 100
1 T ukur 2 jam 4 jam 2 jam
T TLV tt 8 jam 4 jam 3 jam
TWA 0 4/8 2/4 = 1 < batas aman
2 T ukur 0 2 jam 2 jam 2 jam
T TLV tt 8 jam 4 jam 3 jam
TWA 0 2/8 2/4 2/3 = 17/12 >batas aman
Noise3. 4 orang pekerja printer di unit percetakan dimana
terdapatoffset press. Masing-masing terpapar sbb:
No. of presses operating
Average Sound Pressure Level (dBA)
Average daily time in operation
(hours)
0 81 4.5
Berapa dosis harian yang diterimanya? dan Equivalent 8-hour Sound Pressure Level (SPL) yang dialami pekerja percetakan tersebut?
These Printers experience an equivalent SPL of ~ 90 dBA
Noise
4. How much longer is an individual, without hearing protection, permitted to work at a location where the noise level has just been reduced from 104 dBA to 92 dBA?
To answer this question, we must first determine the OSHA permitted duration, in hours, for each of the two identified noise levels.
Tmax = 8 / [2(L-90)/5]
For an SPL of 104 dBA: Tmax @ 104 dBA= 8 / [2(104-90)/5] = 1.149 hours
For an SPL of 92 dBA: Tmax @ 92 dBA= 8 / [2(92-90)/5] = 6.063 max @ 92 dBA
hours
The additional time permitted at the lesser noise level of 92 dBA, ΔTmax, is simply the difference between these two OSHA permitted time intervals; thus:
ΔTmax=6.063 – 1.149 = 4.914 hours
This individual can spend an additional 4.9 hours at a 92 dBA noise level
