ABC of Work Related Disorders: OCCUPATIONAL HEARING LOSS AND VIBRATION INDUCED DISORDERS
Authors: C M Jones
Journal: BMJ (1996)

In 1908 the annual report of the Chief Inspector of Factories stated: Incidence of occupational hearing loss "men employed in certain trades are liable to have their sense of * Department of Social Security estimated that hearing seriously impaired, if not entirely destroyed in the course of 13 000 workers received benefits in 1992 * It is the third commonest assessed claim (after time, as a result of long continued exposure to loud noise."It is only in hand-arm vibration syndrome and tenosynovitis) recent decades that this situation has begun to change.* The OPCS Disability Survey (1985-8) estimated This irreversible sensorineural deafness is caused by damage to the that 52 500 people were affected in England and hair cells of the organ of Corti in the cochlea.It can be the cause of Wales accidents due to failure to hear warning signals.It reduces the quality 103 100 people had deafness, tinnitus, or other of life and, especially in elderly people, produces social isolation.If ear conditions caused by work and a further tinnitus is prominent psychiatric symptoms can occur.18 300 thought that their ear condition had been made worse by work Clinicalpresentation Noise induced hearing loss develops insidiously.A gradual loss of clarity in perceived speech occurs, which is often attributed to inattention or to others not speaking clearly because when the sufferer Causes of deafness looks at speakers he qr she can understand them.Difficulty in Sensorineural loss understanding others in a crowd is, in the same way, presumed to be * Congenital deafness (associated with mateal l due to competition with background noise (perceptual rivalry).rubella or flu or prenatal medication) Eventually, the sufferer realises that others do not have this problem.* Familial deafness This realisation may come suddenly, such as when a telephone with an * Birth trauma electronic bleep is bought to replace one with a bell * Childhood illnesses (such as measles (usually bilateral deafness), mumps (unilateral), encephali- A,high pitched tinnitus, initially intermittent, becomes continuous in tis, meningitis, cerebral abscess, typhus) up to 20% of cases and can be a presenting symptom.The other * Ototoxic drugs feature (usually revealed on direct questioning) is loudness recruitment: Streptomycin and some other antibiotics at a certain volume perceived sound suddenly becomes more intense.(such as gentamicin and neomycin) Anti-rheumatic drugs Diagnosis Diuretics Quinine, nicotine, alcohol, and aspirin As well as asking about current symptoms, the doctor taking a * Fracture of base of skull patient's history should cover other possible causes of sensorineural and * Acoustic neuroma (unilateral deafness) conductive deafness.Both social and work related exposure to noise * Meniere's disease should be reviewed, including the firing of guns (military and sporting), .Presbycusis playing in pop groups, and listening to amplified music.To help assess Conductive loss the level of noise at work, a useful rule of thumb is that voices need to * Impacted earwax be raised to communicate over a distance of one metre at 90 dB(A).* Ruptured eardrum (blow to head or explosion) A check should be made of the present and past use of hearing * Blockage of eustachian tube * Ossicular dysfunction protectors, their type, and how often they are used.Dislocation Examination by otoscopy and tuning fork tests can exclude other Otitis media or fluid causes of deafness.The diagnosis is usually made by air and bone Employers have a general duty to * Make, review, and record assessments of noise * Reduce damage to hearing of employees * Reduce exposure to noise by methods other than use of ear protectors * Provide hearing protection * Create "ear protection zones" * Use and maintain equipment for reducing exposure to noise * Provide information, instruction, and training Manufacturers are required to provide noise levels of equipment that they have supplied Vascular * Trauma * Polyarteritis nodosa