Implantable Hearing Aid Using a Piezoelectric Ossicular Vibrator: A Speech Audiometric Study

Abstract

The speech discrimination provided by a piezoelectric implantable hearing aid (IHA) was compared to that by a conventional hearing aid (CHA) using speech audiometric studies in seven patients. Recognition of monosyllabic and bisyllabic words was measured using word lists recorded on a compact disc with and without background noise. The intensity of speech sound was 65 dB SPL, while that of background noises varied from 65 to 75 dB SPL. The ear canal opposite the test ear was closed with a clay mold to avoid perception of the test sound through the contralateral ear. On monosyllabic test without noise, speech discrimination scores by the IHA and the CHA showed no significant difference. However, with noise of 65 dB SPL, the IHA outperformed the CHA. When the intensity of the noise increased to 70 or 75 dB SPL, the scores by both devices decreased, but a significant difference was noted between the two. On the bisyllabic test, the results were almost identical with those on the monosyllabic test. These findings indicate that speech recognition by the IHA was superior to that by CHA under noisy circumstances.

Key Words:

• Piezoelectric vibrator
• Middle ear implant
• Speech discrimination