Yoshida M, Fujimura K, Makishima K
Department of Otorhinolaryngology, University of Occupational and Environmental Health, School of Medicine, Kitakyushu.
Nihon Jibiinkoka Gakkai Kaiho. 1997 Dec;100(12):1459-64. doi: 10.3950/jibiinkoka.100.1459.
Otoacoustic emissions evoked by electrical stimulation of the cochlea were measured in guinea pigs. Alternating current with acoustic frequencies was delivered directly to the scala tympani and the vestibuli of the basal turn by using a constant current stimulator made in our laboratory. The amplitude of the electrically evoked otoacoustic emmisson (EEOAE), which was 21.0 dB SPL in response to 2 kHz electrical stimuli of 120 microArms, was decreased gradually with anoxia of the animal and was reduced to below the noise level by extirpation of the ossiculum. The EEOAEs rose with a delay of 100 microseconds from the beginning of the stimulus, and reached maximum amplitude within three cycles. The output of EEOAE was magnified in a linear manner as the stimulus current increased from 10 to 200 microArms. The averages and standard deviations of the EEOAE output at the stimulus level of 170 microArms in six animals were 20.5 +/- 4.1 dB SPL for 1 kHz, 23.3 +/- 4.8 dB SPL for 2 kHz, 10.5 +/- 6.0 dB SPL for 3 kHz, 17.1 +/- 4.7 dB SPL for 4 kHz, 13.6 +/- 4.4 dB for 5 kHz and 18.3 +/- 4.8 dB SPL for 6 kHz. Measurement of EEOAE, in which stable responses could be obtained with simple and easy preparation, was considered a potential procedure for assessing the electromotility of the cochlear outer hair cells in vivo.
在豚鼠身上测量了电刺激耳蜗诱发的耳声发射。通过使用我们实验室自制的恒流刺激器，将具有声学频率的交流电直接输送到蜗底的鼓阶和前庭阶。电诱发耳声发射（EEOAE）的幅度，在120微安的2千赫电刺激下为21.0分贝声压级，随着动物缺氧而逐渐降低，并且通过切除听小骨而降低到噪声水平以下。EEOAE从刺激开始起有100微秒的延迟上升，并在三个周期内达到最大幅度。随着刺激电流从10微安增加到200微安，EEOAE的输出呈线性放大。六只动物在170微安刺激水平下EEOAE输出的平均值和标准差，对于1千赫为20.5±4.1分贝声压级，对于2千赫为23.3±4.8分贝声压级，对于3千赫为10.5±6.0分贝声压级，对于4千赫为17.1±4.7分贝声压级，对于5千赫为13.6±4.4分贝，对于6千赫为18.3±4.8分贝声压级。EEOAE的测量，通过简单且容易的准备就能获得稳定的反应，被认为是一种在体内评估耳蜗外毛细胞电运动性的潜在方法。
