In Bing test, on alternately compressing and releasing the external acoustic meatus, the sound increases and decreases. What does this indicate?

Bing test It is a test of bone conduction which examines the effect of occlusion of the ear canal and the hearing. A vibrating tuning fork is placed on the mastoid while the examiner alternately closes and opens the ear canal by pressing on the tragus inwards. A normal person / one with sensorineural hearing loss hears louder when ear canal is occluded and softer when the canal is open. A patient with conductive hearing loss will appreciate no change.