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? – 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 Noise spectrum Overall noise exposure Duration of exposure Individual susceptibility.

Type of noise Steady state noise Intermitent noise Fluctuation noise Impulse noise

Effect of noise Noise induced hearing loss – Temporary – permanent Rupture of ear drum Dislocation os ossicle Speech interference Annoyance Other effect – 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 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 Competent person To know the noise level Mapping the noise level >85 dB (action level) – do HCP < 85 dB – no HCP

Noise Control 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 – 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. – Sound reduction properties – Comfort of worker – Cost – Approved by DOSH.

Record Keeping Name Job Location of employee Base line audiogram Occupational history Medical examination Keep record for 5years after stop work.