A decrease in air conduction sensitivity may be produced in some individuals by pressure exerted on the pinna during audiometric testing. The pressure of the earphone against the pinna may result in the partial closure or complete collapse of the external auditory meatus. Recognition of this condition is the responsibility of the audiologist and otologist. Failure to identify this condition properly may lead to the incorrect diagnosis of conductive hearing loss.
Bess JC. Ear Canal CollapseA Review. Arch Otolaryngol. 1971;93(4):408–412. doi:10.1001/archotol.1971.00770060600009