title: Hearing thresholds with direct bone conduction versus conventional bone conduction.
abstract: Some patients who need hearing aids are unable to use an aid which transmits the sound via the external ear canal but have to use a bone-conduction hearing aid. The pressure needed to apply the transducer often gives the patient discomfort, and the attenuating effect of the skin gives poor electroacoustical function of the aid. A permanent skin penetration has made it possible to develop a bone-anchored hearing aid with all components in one housing. Ten patients have been equipped with such an aid. This paper deals with a comparative hearing threshold measurement on 10 patients. Békésy audiometry was performed and a conventional Oticon (A-type) transducer was used. In the frequency range 600 to 6 000 Hz, there was a lowering of 10-20 dB in thresholds when skin penetration was performed. This lowering in thresholds means lower transducer distortion, lower electrical gain, and lower power consumption to produce a given sensation level.
mesh_terms: D000158:Acoustic Impedance Tests; D000293:Adolescent; D000328:Adult; D000368:Aged; D001301:Audiometry, Pure-Tone; D001309:Auditory Threshold; D001844:Bone Conduction; D005260:Female; D006310:Hearing Aids; D034381:Hearing Loss / Q000628:therapy*; D006314:Hearing Loss, Conductive / Q000628:therapy*; D006319:Hearing Loss, Sensorineural / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged