1993 Fiscal Year Final Research Report Summary
Electric Response from cochlea by speech sound
| Project/Area Number |
04671039
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
Otorhinolaryngology
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SHOJI Kazuhiko Kyoto Univ., Fac.of Med., lecturer, 医学部, 講師 (60196582)
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| Co-Investigator(Kenkyū-buntansha) |
KOJIMA Hisayoshi Kyoto Univ., Fac.of Med., assoc.Prof., 医学部, 助教授 (10127079)
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| Project Period (FY) |
1992 – 1993
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| Keywords | cochlea / speech sound / CAP / LASER |
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| Research Abstract |
Cochlear electrical responses have been well studied all over the world so far. Most researchers have used simple click or sinusoidal waveform as sound stimuli to evaluate such cochlear functions as frequency selectivity. However such simple sound stimuli are not suitable to know how the cochlea works in speech perception, because speech sound consists of very complicated sound signal that changes rapidly in both frequency and amplitude. We have carried out a very preliminary study for the cochlear electric response of a guinea pig against speech signal. The results showed CAP(compound action potentials) may be a very important indicator among cochlear electric responses, since CAP appears just on the consonants of the speech sound /YABU NO NAKA KARA USAGI GA PYOKON TO DETE KIMASHITA/. Detailed study is scheduled to know the relation between the amplitude of CAP and the sort of consonants, especially non-plosive consonants.
We also irradiated low power LASER (30mW Ga-AL-As diode LASER, with a wavelength of 790nm) directly on the round window membrane of guinea pig to investigate whether LASER irradiation have effects on the cochlea. In all guinea pigs, the amplitude of CAP was reduced to 60-80% immediately after the irradiation and was reverted the original level soon after the end of the irradiation.
We think CAP plays an important role in speech recognition and irradiation of low power LASER may affect it by the reduction of CAP.
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