Response latencies and amplitudes of cABR evoked using consonant vowel /da/ and compound click-sawtooths sounds

A total of twenty ears from ten healthy participants (5 females and 5 males), aged 69 between 20 and 35 years (average 28 years), were enrolled. All participants had normal hearing acuity that was defined as the pure-tone hearing threshold levels of 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz, and 8000 Hz were better than 25 dB HL. The auditory evoked potentials (AEPs) were evoked and acquired by the commercial system (SmartEP, Intelligent Hearing Systems, Miami, USA). The acoustic stimulations were the 40-ms synthetic syllable /da/ (CV-da) and the compound click-sawtooths (CSW) and were delivered by insert earphones (ER-2A) . CSW is an electrically generated sound that starts with a 100-us click, followed by a 10-ms interval of zero amplitude, and finally goes with three cycles of 100-Hz sawtooth. CSW has the same duration of 40 ms as CV-da and similar time-lock features with CV-da, however, is sparse of stimulation energy between click and onset of sawtooth waves as well as between the three sawtooth waves. Electrode montage was non-inverting electrode fixed on high forehead (Fz) and inverting electrodes fixed on both earlobes (Ai). Low forehead (Fpz) served as the reference electrode. AEPs were acquired by averaging two blocks of 2000 repetitions for both stimuli. Peaks V, A, C, D, E, and F of response waveforms were determined, the latency and amplitude of each peak were recorded for statistical analysis. The
response amplitudes were significantly greater for CSW and the latencies were
significantly shorter for CSW. The latency-intensity functions were also greater for
CSW. For CSW, adjustments of energy component can be made without causing
biased changes of the other. CSW may also be used in future basic research and clinical applications of cABR.

总计二十名来自十位健康受试者（其中女性五名，男性五名）的耳朵被纳入本实验，受试者年龄介于20至35岁之间，平均年龄为28岁。所有受试者的听力敏锐度均正常，具体表现为250 Hz、500 Hz、1000 Hz、2000 Hz、4000 Hz和8000 Hz纯音听阈水平均优于25 dB HL。听觉诱发电位（AEPs）由商业系统（SmartEP，Intelligent Hearing Systems，迈阿密，美国）诱发并采集。声学刺激包括40毫秒的合成音节/da/（CV-da）以及复合敲击-锯齿波（CSW），并由插入式耳机（ER-2A）提供。CSW是一种通过100微秒的敲击声开始，随后是10毫秒的零幅度间隔，最后以100 Hz锯齿波的三周期结束的电声。CSW的持续时间与CV-da相同，且具有相似的时间锁定特性，然而，在敲击声与锯齿波开始之间以及三个锯齿波之间，刺激能量较为稀疏。电极布置为非倒相电极固定于额部上方（Fz）和双耳垂上（Ai），低额部（Fpz）作为参考电极。AEPs通过对两种刺激各2000次重复的平均值进行采集。响应波形中的V、A、C、D、E和F峰值被确定，每个峰值的潜伏期和幅度均被记录以进行统计分析。对于CSW，可以在不引起其他成分偏置变化的情况下调整能量成分。CSW还可用于未来cABR的基本研究和临床应用。