As per Dobie's criteria, ONIHL is a sensorineural and progressive hearing loss with loss always being more at 30006000 Hz than 500-2000Hz.
ONIHL is due to destruction of cochlear hair cells or damage to their mechano-sensory hair bundles caused by continuous noise exposure of >85dB(A) for 8 hours at the work place.
2) Even though ONIHL is preventable, there is no evidence that this is realized in practice.
As ONIHL progresses, individuals may have difficulty understanding high-pitched voices (e.
The presence of 4000Hz notch is a classical sign of ONIHL.
They are responsible for transducing higher frequencies and this accounts for the high frequency hearing loss found in ONIHL.