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Beyond the pure-tone audiogram

Tympanometry & Otoacoustic Emissions

A pure-tone audiogram tells you how well someone hears. Tympanometry tells you how the eardrum and middle ear are behaving - it varies air pressure in the ear canal and measures how compliance changes. That distinguishes a conductive…

Tympanometry answers a different question

A pure-tone audiogram tells you how well someone hears. Tympanometry tells you how the eardrum and middle ear are behaving - it varies air pressure in the ear canal and measures how compliance changes. That distinguishes a conductive problem such as fluid, a perforation or eustachian tube dysfunction from a sensorineural one. Two workers with identical audiograms can have entirely different causes, and only one of them is about noise.

Why that matters for a shift

A standard threshold shift caused by middle ear fluid is not occupational hearing loss, and treating it as such misdirects your programme and can put a recordable entry on your log that does not belong there. Tympanometry at the point of a suspected shift often explains it immediately.

Otoacoustic emissions, and when they earn their place

OAEs measure sound produced by the outer hair cells in response to stimulation. They require no response from the person being tested, which makes them valuable where a behavioural audiogram is unreliable - language barriers, cognitive impairment, or a suspicion of exaggerated thresholds. They are also sensitive to early cochlear change, sometimes before it appears on the audiogram.

What none of this is

These are screening and surveillance measures within an occupational programme. They do not constitute a diagnostic audiological evaluation, and where findings warrant one we refer rather than extending beyond what the setting supports.

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Sources

Primary regulations and standards referenced above. Where a standard is published commercially it is named in full rather than linked to a copy.