Electrocochleography in Noise-induced temporary threshold shift.
- Author:
Eui Cheol NAM
1
Author Information
1. Department of Otolaryngology, College of Medicine, Kangwon National University, Chunchon, Korea. birdynec@hotmail.com.
- Publication Type:Original Article
- Keywords:
evoked-response audiometry;
noise-induced hearing loss
- MeSH:
Adult;
Audiometry, Evoked Response*;
Audiometry, Pure-Tone;
Hearing Loss, Noise-Induced;
Humans;
Noise
- From:Korean Journal of Otolaryngology - Head and Neck Surgery
2001;44(6):583-587
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND AND OBJECTIVES: Early detection and monitoring are the most important measures in the prevention of development and progression of noise-induced hearing loss (NIHL). Electrocochleography (ECoG) is known as a sensitive evoked-response test to evaluate changes in cochlear function. Through the investigation about the changes of ECoG in development of noise-induced temporary threshold shift (NITTS), we intended to evaluate the usefulness of ECoG on early detection of NIHL. MATERIALS AND METHODS: Ten healthy adult participants (20 ears) were exposed to 90.3~105.0 dB broad-band noise for 3 hours in a computer-game room. Pure-tone audiometry (PTA) and ECoG were performed before the exposure, immediately after and 24 hours after the exposure. RESULTS: Before the exposure, mean PTA threshold was 6.1+/-2.6 dB, which was significantly increased to 12.0+/-3.2 dB immediately after the exposure, and recovered to 5.5+/-2.4 dB at 24 hours later. Marked increment of SP/AP (summating potential/action potential) ratio was observed simultaneously with the development of TTS and was normalized after its resolution. The mean ratio was 0.23+/-0.17 before the exposure, 0.43+/-0.16 on TTS phase, and 0.24+/-0.18 on resolution. CONCLUSION: The result of this study suggest that SP/AP ratio of ECoG might have applicability for early detection and monitoring of NIHL.
