Definisi dan pengertian. Kebisingan Industri. Inside NOISE. What is noise?

(1)

Kebisingan Industri Definisi dan pengertian

Bising = suara-suara yang tidak dikehendaki

Definisi secara ilmiah = sensasi yang diterima telinga sebagai akibat fluktuasi tekanan udara ‘superimposing’ tekanan atmosfir/udara yang steady

Bising = sejenis vibrasi/energi yang dikonduksikan dalam media udara, cairan, padatan, tidak tampak, dan dapat memasuki telinga serta menimbulkan sensasi pada alat dengar

Inside NOISE

What is noise?

– Definition, energy conducted and sensed, properties:

intensity/pressure, frequency, exposure,

Why unwanted?

– 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 udara yang stabil.

Telinga akan merespons fluktuasi-fluktuasi

kecil tersebut dengan sensitivitas yang

sangat besar.

(2)

Properties of noise?

Karakteristik bising

1. Intensitas/tekanan (sound pressure/intensity)

2. Frekuensi

3. Durasi eksposur terhadap bising Ketiga karakteristik diperlukan karena:

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

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, contoh gergaji bundar.

Impact noise, kejutan singkat berulang, contoh riveting

Intermitten noise, bising terputus, contoh lalu lintas pesawat

Contoh…

(3)

Tekanan = Sound Pressure

Manusia dapat 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 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

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)

Intensity level dB=10 Log (IT/IA)

Sound pressure level (tekanan bunyi) = 20 log (IT/IA), karena intensitas sebanding dengan kuadrat tekanan bunyi.

Ruang kelas: ?dB

Rumah

Restauran

Berbisik

Berteriak

Jet plane

The decibel

SOUND INTENSITY

SOUND SOURCE LINEAR UNITS

Bel

LOGARITHMIC UNITS Decibel

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

(4)

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

Pressure

Pa Bel (B) Decibel (dB)

Threshold of hearing 0,00002 0 0

Quiet office 0,002 4 40

Ringing alarm clock at 1 m 0,2 8 80

Ship's engine room 20 12 120

Turbo jet engine 2000 16 160

Sound intensities

Frekuensi

Adalah jumlah getaran dalam tekanan suara per satuan waktu (Hertz atau cycle per detik), frekuensi dipengaruhi ukuran, bentuk dan pergerakan

sumber, 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 taraf kebisingan dari setiap frekuensi dihitung Leq

Leq = ekuivalen noise level/ekuivalen energi level

Leq = 10 log₁₀(Σ 10 ^Lpi/10)

(5)

²

atau

1microbar = 1 dyne/cm

²

L =10 log ( Σ 10

^Li/10

) (sumber banyak)

=10 log (10

^L1/10

+ 10

^L2/10+…

)

Sumber > 1….. (Contoh)

=10 log ( Σ 10

^Li/10

)

(banyak sumber)

=10 log (10

^L1/10

+ 10

^L2/10+…

)

Perbedaan antara sumber

bunyi

ΣdBA yang turun ditambah ke bunyi terbesar

0 3,0

1 2,6

2 2,1

3 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

²

atau

1microbar = 1 dyne/cm

²

(6)

L =10 log ( Σ 10

^Li/10

) (sumber banyak)

=10 log (10

^L1/10

+ 10

^L2/10+…

)

Sumber > 1….. (Contoh)

=10 log ( Σ 10

^Li/10

)

(banyak sumber)

=10 log (10

^L1/10

+ 10

^L2/10+…

)

Perbedaan antara sumber

bunyi

ΣdBA yang turun ditambah ke bunyi terbesar

0 3,0

1 2,6

2 2,1

3 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

14 Perbedaan antara 2 tingkat bising, dB(A) 3

2,5

12 10 8 6 4 2 0,5 1,5 2

1

Decibel yang ditambahkanpada tingkatkebisinganlebihtinggi Perbedaan (dB)

Tambah pada yg lebih tinggi

0 atau 1 3

2 atau 3 2

4 – 9 1

10+ 0

Why unwanted?

Health Effect, age, psychological:

annoyed, concentration, rest/relax

problem, communication annoyance,

physiological: blood, heart, hearing loss,

nausea, muscle control, acoustic trauma

(permanent) vs temporary,

(7)

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.

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 of 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

(8)

Gangguan pendengaran

Pemaparan pada suara tinggi dan periode/durasi yang lama akan

menyebabkan sel syaraf pendengar dan rambut pada corti over aktif sehingga menimbulkan kehilangan pendengaran permanen

Pengukuran kebisingan

• Mengukur overall level sound level meter (satuan dBA)

• Mengukur kebisingan pada setiap level frekuensi SLM dengan frequency analyzer

• Penentuan eksposur kebisingan pada pekerja noise dosimeter (satuan dBA)

Alat ukur

Sound level meter, mencatat keseluruhan suara yang dihasilkan tanpa

memperhatikan frekuensi yang

berhubungan dengan bising total (30-130 d) – (20-20.000Hz)

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

SOUND LEVEL METER

NOISE

MEASUREMENT KIT

NOISE DOSIMETER

(9)

PENGUKURAN PADA

PEKERJA DOSEBADGER

Pneumatic

chip hammer 103-113 Crane 90-96 Jackhammer 102-111 Hammer 87-95 Concrete joint

cutter 99-102 Gradeall 87-94

Skilsaw 88-102 Front-end

loader 86-94

Stud welder 101 Backhoe 84-93

Bulldozer 93-96

Garbage disposal (at 3 ft.)

80

Earth Tamper 90-96 Vacuum

cleaner 70

(10)

Pengukuran akibat bising

Untuk mengevaluasi akibat

pemaparan terhadap kehilangan pendengaran, kenyamanan, interferensi komunikasi dan mengumpulkan informasi untuk pengontrolan.

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

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%

Ketulian

= berkurangnya ketajaman pendengaran

dibanding/terhadap orang normal (15 dB)/ gol usia

• Ada 2 macam:

-permanen: karena penyakit, usia tua, obat, trauma, dan kebisingan

-temporer:akibat ekposur bising, dapat pulih setelah istirahat beberapa saat tergantung keparahan

• Ketulian temporer akan menjadi permanen bila terus terekpos bising (dari rumah, tempat umum, rekreasi, musik, industri, dll.)

• Secara mekanisme: ketulian ada 2:

-konduktif:peralatan konduksi suara rusak akibat trauma atau sakit

-sensorinueral: akibat persyarafan pendengaran rusak

Audiometric test

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Audiometric test

Current OSHA Standards

•1926.52 Occupational Noise Exposure

•TABLE D-2 - PERMISSIBLE NOISE EXPOSURES

Duration per day, hours Sound Level dBA slow response

8 90

6 92

4 95

3 97

2 100

1 1/2 102

1 105

1/2 110

1/4 or less 115

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

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

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)

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Case Study 1 Conclusion

"Temporary threshold shift" example

Common in persons exposed to high noise

Represents transient hair cell dysfunction

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 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

(13)

Damage risk criteria

Variation in individual susceptibility

The total energy of the sound

The frequency distribution of the sound

Other characteristics of the noise exposure, 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 ear

Pengendalian kebisingan

Pengendalian dilakukan di 3 bagian: SUMBER, RUANG ANTARA sumber dan penerima/pekerja, pada

PENERIMA/PEKERJA Urutan pengendalian paling efektif:

• Kurangi/hilangkan sumber bising

• Pengendalian pathway: jarak diperjauh dengan perisai/isolator/automatisasi

• Perlindungan penerima dari bising (APD)

SUMBER PATHWAY/MEDIA PENERIMA/RECEIVER

•Cara teknis:

APD Perpanjang jarak

Reduksi waktu Perisai

Insulasi sumber

Isolasi pekerja Absorpsi/damping

Substitusi

PENERIMA PATHWAY

SUMBER

•Cara medis:

Pemeriksaan ketajaman pendengaran secara periodik Penempatan pekerja sesuai dengan kepekaan thd bising Monitor ketulian temporer

•Cara manajemen:

Reduksi waktu eksposur

Diklat pemakaian dan pemeliharaan APD

(14)

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.

– 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 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 administrative 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.

(15)

Noise control

Noisy operations may be conducted outside normal working hours to reduce the number of 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 them sound radiation proper use of machine mountings insulates the machine and reduce the transmission of vibration

Control of noise by absorption

Travels out in all direction

When encounter walls reflected

Total noise exposure within the room = direct + reflected noise

Application of sound absorption

material (However, limited: no

effect on direct noise).

(16)

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.

Therefore protection: ear plugs

Properly worn: 25 – 400 dB protection

Degree of discomfort employee education is adequate

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 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.

Durasi per hari

Tingkat bising 8

6 4 3 2 1,5

1

¾

½

¼

90 92 95 97 100 102 105 107 110 115

Faktor-faktor yang mempengaruhi bising

Tipe bising: menerus dan terputus

Lokasi pekerja

Waktu kerja

(17)

NAB Kebisingan di lingkungan kerja

USA (TLV ACGHI) t (eksposur) jam dB(A)

8 90

6 92

4 95

3 97

2 100

1,5 102

1 105

0,5 110

<0,25 115 kebisingan impulsif < 140 dB

t dBA

8 85

4 88

2 91

1 94

30 mnt 97

15 mnt 100 7,5 mnt 103 3,75 mnt 106 1,88 mnt 109

dst

dilarang > 140 dB

INDONESIA Permen 51/1999

Waktu pemaparan vs dB (TLV)

Waktu Waktu Waktu

Waktu pemaparan pemaparan pemaparan pemaparan (jam) (jam) (jam) (jam) dB dB dB dB

8 88 8 6 66 6 4 44 4 2 22 2 1,5 1,51,5 1,5 1 11 1 0,5 0,50,5 0,5

<0,25

90 90 90 90 92 92 92 92 95 95 95 95 100 100 100 100 102 102 102 102 105 105 105 105 110 110 110 110 115 115 115 115 ((((SumberSumberSumber: FHI)Sumber: FHI): FHI): FHI)

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

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

(18)

BARRIER-BARIER ATAU PANEL

ISOLASI PEKERJA/MESIN DI TEMPAT BISING

BAHAN ABSORBER BAHAN BARRIER

Noise control can be complex

Use noise control consultants to help solve your problems if complex Engage employees in process

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

(19)

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 Zealand Standard AS/NZS 1270:2002

Class and specification of hearing protectors

SLC

₈₀

Class

May be used up to this noise exposure level

10 to 13 1 90 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

(20)

Reduction in protection provided by hearing protectors with decreased wearing time

Example:

Effectiveness of wearing an ear muff with a rating of 30 dB for an exposure time of one hour

Wear time Effective attenuation 60 minutes 30 dB

55 minutes 11 dB

50 minutes 8 dB

45 minutes 6 dB

Our challenge

Away from …

Noise assessment as the end point

Reliance on hearing protection Towards …

Control of noise risks through prioritised action plans

Introducing equipment with good noise and vibration characteristics – ‘Buy Quiet’

TWA untuk kebisingan: berdasarkan standar kebisingan.

Jumlah jam dB(A)

1,5 102

1,0 105

0,75 107

0,5 110

0,25 115

Jumlah jam dB(A)

8 90

6 92

4 95

3 97

2 100

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 STANDA

R

KEBISING AN

Noise

3. 4 orang pekerja printer di unit percetakan dimana terdapat

offset press. Masing-masing terpapar sbb:

Berapa dosis harian yang diterimanya? dan Equivalent 8-hour Sound Pressure Level (SPL) yang dialami pekerja percetakan tersebut?

No. of presses operating

Average Sound Pressure Level (dBA)

Average daily time in operation

(hours)

0 81 4.5

1 93 2.1

2 96 1.0

3 98 0.4

(21)

Jawab:

5 / ) 90 max (

2 8

= _L−

T

5 / ) 90 81 max (

2 81 8

@ dBA= ₋

T = 27.858 jam

Untuk SPL 81 dBA:

5 / ) 90 93 max (

2 93 8

@ dBA= ₋

T = 5.278 jam

Untuk SPL 93 dBA:

5 / ) 90 96 max (

2 96 8

@ dBA= ₋

T = 3.482 jam

Untuk SPL 96 dBA:

5 / ) 90 98 max (

2 98 8

@ dBA= ₋

T = 2.639 jam

Untuk SPL 98 dBA:

Noise

n

i T

C T

D C ⁿ

n

i i

1 max max

2 max

1 max

....

2 1

+ + +

=

∑

=

639 . 2

4 . 0 482 . 3

0 . 1 278 . 5

1 . 2 858 . 27

5 . 4

inter = + + +

Dpr _{= 0.998}

Now, expressing this result as a percentage as required by the problem statement, we have: D_printer= 99.8%

The Printing Company that employs these four Printers is not in violation of any established OSHA SPL dosage standards.

Noise

L

_equivalent

= 90 + 16.61 log[D]

L

_equivalent

= 90 + 16.61 log[0.998]

= 89.987

~ 90 dBA

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?

(22)

To answer this question, we must first determine the OSHA permitted duration, in hours, for each of the two identified noise levels.

T_max= 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 hours

The additional time permitted at the lesser noise level of 92 dBA, ∆T_max, is simply the difference between these two OSHA permitted time intervals; thus:

∆Tmax=6.063 – 1.149 = 4.914 hours

This individual can spend an additional 4.9 hours at a 92 dBA noise level