Audiology Department, City Hospitals Sunderland, Sunderland, United Kingdom.
Hearing and Balance Centre, Institute of Sound and Vibration Research, University of Southampton, United Kingdom.
Ear Hear. 2019 May/Jun;40(3):447-457. doi: 10.1097/AUD.0000000000000639.
Auditory brainstem responses (ABRs) are commonly generated using simple, transient stimuli (e.g., clicks or tone bursts). While resulting waveforms are undeniably valuable clinical tools, they are unlikely to be representative of responses to more complex, behaviorally relevant sounds such as speech. There has been interest in the use of more complex stimuli to elicit the ABR, with considerable work focusing on the use of synthetically generated consonant-vowel (CV) stimuli. Such responses may be sensitive to a range of clinical conditions and to the effects of auditory training. Several ABR features have been documented in response to CV stimuli; however, an important issue is how robust such features are. In the current research, we use time- and frequency-domain objective measures of quality to compare the reliability of Wave V of the click-evoked ABR to that of waves elicited by the CV stimulus /da/.
Stimuli were presented to 16 subjects at 70 dB nHL in quiet for 6000 epochs. The presence and quality of response features across subjects were examined using Fsp and a Bootstrap analysis method, which was used to assign p values to ABR features for individual recordings in both time and frequency domains.
All consistent peaks identified within the /da/-evoked response had significantly lower amplitude than Wave V of the ABR. The morphology of speech-evoked waveforms varied across subjects. Mean Fsp values for several waves of the speech-evoked ABR were below 3, suggesting low quality. The most robust response to the /da/ stimulus appeared to be an offset response. Only click-evoked Wave V showed 100% wave presence. Responses to the /da/ stimulus showed lower wave detectability. Frequency-domain analysis showed stronger and more consistent activity evoked by clicks than by /da/. Only the click ABR had consistent time-frequency domain features across all subjects.
Based on the objective analysis used within this investigation, it appears that the quality of speech-evoked ABR is generally less than that of click-evoked responses, although the quality of responses may be improved by increasing the number of epochs or the stimulation level. This may have implications for the clinical use of speech-evoked ABR.
听觉脑干反应（ABR）通常使用简单的瞬态刺激（例如，点击或纯音爆发）产生。虽然由此产生的波形无疑是有价值的临床工具，但它们不太可能代表更复杂的、与行为相关的声音（如言语）的反应。人们一直有兴趣使用更复杂的刺激来引出 ABR，其中大量工作集中在使用合成产生的辅音-元音（CV）刺激。这种反应可能对多种临床情况和听觉训练的效果敏感。已经记录了 CV 刺激下的几个 ABR 特征；然而，一个重要的问题是这些特征的稳健性如何。在当前的研究中，我们使用时域和频域质量客观测量来比较点击诱发 ABR 的波 V 与 CV 刺激 /da/ 诱发的波的可靠性。
在安静环境中，以 70 dB nHL 的强度向 16 名受试者呈现刺激 6000 个时段。使用 Fsp 和 Bootstrap 分析方法检查了跨受试者的反应特征的存在和质量，该方法用于为时间和频域中的个体记录分配 p 值。
在 /da/ 诱发反应中确定的所有一致峰的振幅均显著低于 ABR 的波 V。言语诱发波形的形态在受试者之间存在差异。几个言语诱发 ABR 波的平均 Fsp 值低于 3，表明质量较低。对 /da/ 刺激反应最稳健的似乎是偏移反应。只有点击诱发的波 V 显示出 100%的波存在。对 /da/ 刺激的反应显示出较低的波可检测性。频域分析显示，与 /da/ 相比，点击引起的活动更强且更一致。只有点击 ABR 在所有受试者中均具有一致的时频域特征。
基于本研究中使用的客观分析，似乎言语诱发 ABR 的质量通常低于点击诱发反应的质量，尽管通过增加时段数或刺激水平可以提高反应的质量。这可能对言语诱发 ABR 的临床应用有影响。
