The output characteristics of an implanted bone conduction prosthesis

So far, the published guidelines for patient selection for the Audiant implanted bone conduction device have been derived from clinical trial rather than experimental study. Theoretical considerations suggest that the guidelines should be frequency specific; the need for this was investigated in a laboratory study. Two independent measures of the maximum output of the Audiant device using both the body-worn and ear-level amplifiers have been performed on two subjects. These lead to maximum output figures for the device ranging from 15 dB HL at 250 Hz to 60 dB HL at 6000 Hz for the body-worn amplifier, and from 6 dB HL at 250 Hz to 42 dB HL at 6000 Hz for the ear-level amplifier. These results suggest that the ear-level amplifier is suitable only for candidates with essentially normal bone conduction thresholds at frequencies of 1000 Hz and below.