The Use Of Circumaural Earphones For Attenuating Ambient Noise In Bone Conduction Audiometry.

Abstract

Auditory sensitivity to a bone-conducted (BC) acoustic stimulus is increased when the ear canal is plugged('occlusion effect'), thus increasing the eardrum-ossicle component. It is desirable to plug the ear against extraneous ambient sound during BC testing, but it is not desirable at the same time to affect the BC threshold. It is found that one of the new circumaural earmuffs does a superior job of insulating the ear from ambient sounds, thus allowing BC testing in otherwise unsatisfactorily noisy audiometric workspaces, while at the same time creating so large a volume of air connected to the ear canal that the occlusion effect is negligible at audiometric frequencies as low as 250 Hz. It is recommended that in some audiometric workspaces such earmuffs be used for BC audiometry. (Author)