Davis H, Hirsh S K
Audiology. 1979 Nov-Dec;18(6):445-61. doi: 10.3109/00206097909072636.
Proper choices of stimuli and of brain stem electric responses allow us to estimate peripheral auditory thresholds at 500, 1 000, 2 000 and 4 000 Hz with an accuracy of about +/- 10 dB. With the help of sedation (secobarbital), such audiograms may be obtained from each ear of a child of any age in a single session. Tone pips (filtered clicks) or very brief tone bursts give a frequency selectivity that is clinically adequate. The rise time must be adjusted to the center frequency. A rise time of two periods with a plateau from zero to one period gives a good compromise between frequency specificity and a synchronous neural discharge. The best threshold indicator for tone pips of 2 000 Hz or higher (or unfiltered clicks) is P6 (Jewett V). At 60 dB nHL its latency is 6.0-7.0 ms (for children of 1 year or older), but near threshold it is 8.0-9.5 ms. An input pass-band of 140-3 000 Hz is appropriate. The best threshold indicator at 500 or 1 000 Hz is a nearly neglected slower wave with a scalp-negative crest at about 10 ms following a 60-dB click. Latency is 15 ms following a 500-Hz tone pip at 15 dB SL. We call this wave "slow negative (ten)" or SN10. To see it well a wider input pass-band such as 40-3 000 Hz is needed. SN10 is usually obscured by P6 or by frequency-following response at stimulus levels above 35 dB SL. The details are given of a clinical routine that allows the determination (+/- 10 dB) of 8 threshold endpoints within about 80 min. Several precautions and limitations are discussed, and also the origin of the SN10 wave.
正确选择刺激方式和脑干电反应，使我们能够以约±10分贝的精度估计500、1000、2000和4000赫兹的外周听觉阈值。借助镇静剂（司可巴比妥），可以在一次检查中从任何年龄儿童的每只耳朵获取这样的听力图。短纯音（滤波后的咔嗒声）或非常短暂的音爆具有临床上足够的频率选择性。上升时间必须根据中心频率进行调整。两个周期的上升时间和从零到一个周期的平台期在频率特异性和同步神经放电之间取得了良好的折衷。对于2000赫兹或更高频率的短纯音（或未滤波的咔嗒声），最佳阈值指标是P6（朱伊特V波）。在60分贝正常听力级时，其潜伏期为6.0 - 7.0毫秒（对于1岁及以上儿童），但在接近阈值时为8.0 - 9.5毫秒。140 - 3000赫兹的输入通带是合适的。在500或1000赫兹时，最佳阈值指标是一个几乎被忽视的较慢波，在60分贝咔嗒声后约10毫秒出现头皮负峰。在15分贝感觉级的500赫兹短纯音后潜伏期为15毫秒。我们将这个波称为“慢负波（十）”或SN10。为了清晰地看到它，需要更宽的输入通带，如40 - 3000赫兹。在高于35分贝感觉级的刺激水平下，SN10通常会被P6或频率跟随反应掩盖。文中给出了一种临床常规方法的详细信息，该方法可在约80分钟内确定8个阈值端点（±10分贝）。讨论了一些注意事项和局限性，以及SN10波的起源。
