Bone Conduction Hearing: Device Auditory Capability to Aid in Device Selection

Abstract

Objectives:

1) Obtain measures of six current bone conduction devices that use a surgically implanted osseointegrated post (Baha Intenso, Baha BP100, Baha BP110, Ponto, Ponto Pro) or a non-surgical module on the teeth (SoundBite). 2) Describe how the measures relate to auditory performance.

Methods:

Compare measures of the six devices on the same laboratory system using identical standards (ANSI, IEC). Outcome Measurements: Maximum vibratory output, maximum gain, linear dynamic range, and frequency range. Independent Variables: Six devices.

Results:

Measures for all devices were highly repeatable (sd of test-retest measures < 0.5 dB) and equivalent to available published results. Maximum output, gain, and linear dynamic range at full-on gain settings were similar for all devices but differed by frequency region. For the frequency range necessary for processing speech (500-2000 Hz), all of the devices have sufficient output, gain, and linear dynamic range. For the frequency range optimal for providing the spatial hearing benefits of understanding speech in noise and speech localization (1500-8000 Hz), the dental device will have 10-20 dB more gain and linear dynamic range than the implantable devices.

Conclusions:

All devices had sufficient output, gain, and linear dynamic range to reach a normal cochlea over a frequency range to provide benefit for processing speech. The dental device has a higher output and larger dynamic range (~20 dB) in the high frequency range (>2000 Hz) that relates to spatial hearing benefits.