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Volume 32 (1989)
- Issue 6 Pages 725-
- Issue 5 Pages 299-
- Issue 4 Pages 223-
- Issue 3 Pages 159-
- Issue 2 Pages 103-
- Issue 1 Pages 1-
Predecessor
Volume 32, Issue 4
Displaying 1-9 of 9 articles from this issue
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as a Causative Factor of Sensorineural Hearing LossTetsuya Tono, Hirokazu Kawano, Kiyo Kano, Yasuaki Ushisako, Tamotsu Mo ...1989 Volume 32 Issue 4 Pages 223-230
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSUpward extension of the jugular fossa into the medial petrous bone or medial high jugular bulb (MHJB) is not a rate radiologic finding. MHJB possibly affects inner ear structures in some cases. We evaluated pure tone audiograms in 22 ears of 20 patients with MHJB who had sensorineural hearing loss from an unknown cause on the same side. Most of these audiograms showed either various degrees of hearing loss in the higher frequencies or total deafness. Among these, 5 out of 7 audiograms of the ears with unilateral hearing loss gave a characteristic pattern with abrupt downward slope from 2000Hz, suggesting that this type of inner ear hearing loss was related to MHJB. A clinical significance of MHJB was discussed as one of the causative factors on the laterality of sensorineural hearing loss.View full abstractDownload PDF (2191K) -
Atsuko Eto, Ginichirnu Icikawa, Norio Uehara, Atsushi Sakurai1989 Volume 32 Issue 4 Pages 231-237
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn 20 infants aged from one month to 5 years old without hearingloss, ABR under sleep condition was recoreded with various stimulus intensities as 100dB, 80dB. The wave forms were devided into the slow components under the filter with 10-200Hz pass band and the fast-slow complex ABR under 10-2000Hz. The results were as follws:
1. The slow positive components were observed with a latency of nearly the same as wave V.
2. The latencies of wave V were stable as the age increased while slow positive and negative waves were not.
3. As one of the characteristics of infants' ABR, a large negative deflection after wave II was observed,View full abstractDownload PDF (678K) -
Takuya Yamakawa, Ginichirou Ichikawa, Norio Uehara, Atsuko Eto1989 Volume 32 Issue 4 Pages 238-243
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSWave IV and V of ABR are not always easy to identify, because of their modality of a compound formation of IV-V complex.
To investigate this IV-V complex of ABR, we have tried to obtain normal variations of the IV-V complex by various recording parametters. such as location of vertex electrodes, stimulus intensity, repetition rate and filter pass-bands.
The results were as follows
1) The discrepancy of the location of active electrodes showed no influense upon the modarity of the IV-V complex.
2) The latency of the wave IV-V complex was shorter than that of wave V.
3) The appearence wave IV-V complex was increased by shortening of repetition rate (from 100ms to 33ms).
4) The appearence of wave IV-V complex was over 30% in normal ABR.View full abstractDownload PDF (505K) -
S. ITO, S. FUNASAKA1989 Volume 32 Issue 4 Pages 244-255
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe frequency specificity of the binaural interaction (BI) of auditory brainstem response (ABR) was investigated in ten normal-hearing young adults.
Special care was taken with respect to stimuls presentation. A novel stimulus paradigm was deviced to rule out the influence of the acoustic refllex on ABR, and to record each response with an almost same signal-noise ratio.
Gaussian shaped tone pulses with carrier frequencies of 1, 2, 4 and 6kHz each were periodically presented in the order of right monaural-left monaural-binaural-leftmonaural-rightmonaural-binaural, with an inter-stimulus interval 22ms.
Both latency and amplitude of the binaural interaction component were evaluated statistically. The latency of BI-except of the latest one-showed an almost linear dependence both on stimulus intensity and stimulus frequency. The amplitude of BI grew greater with decreasing frequency, and the visual detection threshold elevated as the stimulus frequency increased.View full abstractDownload PDF (868K) -
Effects of Repetition RateA. Uno, K. Kaga1989 Volume 32 Issue 4 Pages 256-262
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSThe purpose of this study is to compare Middle-Latency-Response (MLR) with evoked potential (EP) from the auditory cortecies (A1) in awake cats. MLR and EP from A1 were recorded simultaneously from eight adult cats. Then the effects of repetition rate on wave configuration were investigated.
As a result, the latency of the wave 8 and NA of MLR resembled N1 and P1, which are the first large negative and positive peaks after Auditory Brainstem Response (ABR) in evoked potencial from the auditory cortex. Also wave 8-NA decreased its amplitude in proportion to N1-P1 when the repetition rate was increased.
The data suggest that the wave 8 and NA of MLR was correlated with the auditory cortex.View full abstractDownload PDF (701K) -
Akira Shimamoto1989 Volume 32 Issue 4 Pages 263-269
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSStudies were made on the factors determining the so-called central frequency of narrow-band action potentials of the cochlea of the guinea pig. Specific attention was paid to the effects of changing intensities of masking noises on the central frequency. Compound action potentials were recorded by applying simultaneous click stimuli with a masking noise supplied through a high-pass filter. Narrow-band action potentials were derived by setting the cutoff frequencies of the filter to an octave band width. The derived responses showed a prolongation in latency when the intensity of the masking noise was increased. The results were analyzed on the assumption that the band pass characteristics of the high-pass filter would act as a determinant of the frequency range at which the responses attained the maximal heights. The assumption predicts that an increase in intensity of masking noise induces a shift of the central frequency toward a lower frequency range, which leads to a prolongation of the response latencies. Discussion is also made on the shift of the central frequency due to a rise of threshold for hearing.View full abstractDownload PDF (798K) -
Masaharu Ishikawa, Ginichirou Ichikawa, Norio Uehara, Hideki Saitou, Y ...1989 Volume 32 Issue 4 Pages 270-274
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAn experimental study on recording of both Electrocochleography (ECochG) and ABR on the time sequential axis was carried out in order to obtain the electro-physiological informations of the pathway from the inner ear to the brain-stem.
Anesthetized adult cats, weighted approximately 4Kg, were used for recording of ECochG and ABR. ECochG was recorded ipsilateral mastoid to promontory of the middle ear cavity between ABR was recorded between vertex to ipsilateral mastoid.
The sequential recording of ECochG and ABR was processed by a minicomputer.
The results were as follows.
1) Sequential recording of ECochG and ABR provided us the auditory electro-physiological aspects at the level of the inner ear and the brainstem.
2) Furthermore their continuity and duplication were clearly identified.
3) N1 of ECochG and wave IV of ABR were clearly detected even if acoustic stimuli with low intensity were applied. Therefore the estimation of the inter-peak latency (IPL) was possible with those cases which showed no components of ABR except wave IV.
4) These experimental data suggested that the sequential recording of ECochG and ABR will be effective for the clinical usage.View full abstractDownload PDF (424K) -
evaluation from a promontory testJunichi Matsushima, Masahiko Kumagai, Chihiro Harada, Kunihiro Takahas ...1989 Volume 32 Issue 4 Pages 275-279
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSAs a speech coding method, a new idea has been proposed to transmit simultaneously the pitch signal and the second formant frequency through an electrode. In this method, an additional stimulation pulse, which is set in proportion to the second formant frequency, is inserted between the pitch pulses.
An promontory test on 36 male deaf patients showed that this new method of speech coding has proven effective for discrimination of five Japanese vowels and also for discrimination among pitch patterns.View full abstractDownload PDF (544K) -
The difference of response based on electrode position on neural excitationShin-ichi Hatsushika, Sotaro Funasaka1989 Volume 32 Issue 4 Pages 280-286
Published: August 31, 1989
Released on J-STAGE: April 30, 2010
JOURNAL FREE ACCESSIn this study the effects of electrode position in the scala tympani on neural excitation with electrical stimulation of the auditory nerve for improvement of multichannel intracochlear implant was examined.
Electrically evoked auditory brainstem response (EABR) recordings were performed on kanamycin induced deaf cats with the scala tympani bipolar stimulation at four different positions (near the cochlear outer wall, spiral ganglion cell, dendrites and in the middle of them) in the scala tympani and the change of distance between electrodes.
After completion of the electrical stimulation, each animal was sacrificed and prepared for histological examination.
EABR thresholds and amplitude growth curves with stimulus intensity (input-output function) were compared with cochlear histological estimates.
The results were as follows;
1) Regardless of electrode position, EABR thresholds became lower and amplitudes became greater as the distance between electrodes was longer.
2) Regardless of the distance between electrodes, EABR thresholds became lower as electrode array positioned from the cochlear outer wall to dendrites.
3) The differences of EABR thresholds with changing the electrode placement were large when the distance between electrodes was short, and vice versa.
4) Amplitude growth curves in each electrode placement were similar to each other as the distance between electrodes was longer.View full abstractDownload PDF (619K)
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