Download Noise at Workplce

Noise at Workplace
Dr. Noor Hassim Ismail
Anatomy of Ear
• 3 parts
– Outer ear
– Middle ear
– Inner ear
• Cochlea- hearing apparatus
• Vestibular- balancing of the body
Pathophysiology of hearing
• How we hear?
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Air conduction
Bone conduction.
Conductive hearing loss
Sensorineural hearing loss
Effects of noise
• Noise definition- unwanted sound.
• Noise unit- intensity –decibel (dB),
frequency(hertz –hz).
• Type of sound based on frequency
– Infrasonic (0-20 Hz) ,
– Audible (20-16,000)
– Ultrasonic (> 16,000)
Factors contributing to noise
hazard
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Noise spectrum
Overall noise exposure
Duration of exposure
Individual susceptibility.
Type of noise
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Steady state noise
Intermitent noise
Fluctuation noise
Impulse noise
Effect of noise
• Noise induced hearing
loss
– Temporary
– permanent
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Rupture of ear drum
Dislocation os ossicle
Speech interference
Annoyance
• Other effect
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Task performances
Intrusion of privacy
tinnitus’
Blood pressure
Fatique
Bood sugar
Gastric acid secretions
• Intermittent noise
– Less effect than steady
state noise
• Impulse noise
– Effect depend on
number of impulse
exposed.
Hearing Conservation Programme
• Indication s for the ed of a HCP
– Difficulty in communication
– Tinnitus after workking
– Temporay losss of hearing
Elements of HCP
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Assessment of noise exposure
Noise control
Audiometric testing programme
Medical evaluation and treatment
Health education and training
Provision of hearing protection
Establishment of proper record keeping.
Assessment of noise
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Competent person
To know the noise level
Mapping the noise level
>85 dB (action level) – do HCP
< 85 dB – no HCP
Noise Control
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Nose reduction activities to less than 85 dB
Engineering control
Administrative control
Both methods
Control strategies:
– Sources
– At path
– Receiver
Education programme
• To educate the workers
• Training every 2 years
• Teach them
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Effect of noise
Control
Personel protective equipment and maintenance
Audiomeric test
Noise regulations
etc
Audiomeric testing programme
• Baseline audiometric test
• Periodic audiometric test
• Objective the test:
– To establish the hearing status.
– To monitor hearing loss during period of
employement
– To identify worker who is secceptible to noise
– To regulate noise hearing programme
Medical Evaluation and treatment
• Abnormal audiogram refer to doctor
• Hearing problems refer to doctor
Povision of hearing protectors
• Ear plugs
• Ear muffs
• Factors deciding type of PPE.
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Sound reduction properties
Comfort of worker
Cost
Approved by DOSH.
Record Keeping
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Name
Job
Location of employee
Base line audiogram
Occupational history
Medical examination
• Keep record for 5years
after stop work.