Chirp-evoked auditory steady-state responses: Optimal parameters for rapid and objective tests of hearing

在安静环境下评估听力阈值的可靠方法在听力学中具有重要意义。对于合作患者，听力图是在听力测试中测量的，而对于非合作患者，如婴儿，听觉诱发电位（AEP）和耳声发射是用来评估听力能力的。特别是从脑电图中提取的听觉诱发电位提供了一种可靠而客观的阈值测量方法。40多年来，点击诱发的听觉-脑干反应（ABR）被用于临床常规评估在宽频率范围内安静的平均阈值，但当需要特定频率的估计时，这种刺激类型不是很有用。一种既定的方法是使用音调脉冲来代替点击，但对这些刺激的反应不够强大，无法用于临床常规。听觉稳态反应（ASSR）是克服上述局限性的一种很有前途的工具。ASSR可以通过强大的统计检验在谱域中进行分析。从临床角度来看，ASSR可以同时在双耳记录多达四个频率是有用的。在过去的几年中，商业实现已经在一些诊所成功地使用。这种方法的局限性是，到目前为止，记录相当耗时。这可以通过刺激和记录参数的最佳选择来克服。本研究的目的是探讨刺激和记录参数对多频环境下临床高度相关的刺激类型啁啾的ASSR的影响。啁啾补偿了行波在耳蜗中的延迟，因此产生了较大的AEP响应幅度。虽然啁啾诱发的ASSR已用于临床，但基本刺激和记录参数对啁啾诱发的ASSR影响的数据尚未得到。具有优化参数的多频啁啾诱发的ASSR可能是客观评估诊所安静中特定频率阈值的最后一步。研究了刺激和记录参数对成年正常听力听者和感音神经性听力损失参与者的影响。这些数据被用作优化参数的基础，以实现稳健和有效的临床ASSR记录。

Reliable methods for the assessment of hearing thresholds in quiet are of fundamental importance in audiology. For cooperative patients, the audiogram is measured in hearing tests whereas in non-cooperative patients such as in infants auditory evoked potentials (AEP) and otoacoustic emissions are used to assess the hearing ability. Especially auditory evoked potentials that were extracted from the electroencephalograms provide a robust and objective measure of threshold in quiet. For over 40 years, click-evoked auditory-brainstem responses (ABR) are used in clinical routine for the assessment of an average threshold in quiet over a wide range of frequencies but this stimulus type is not very useful when a frequency-specific estimate is required. An established approach is to use tone pulses instead of clicks but the responses to these stimuli are not robust enough for a clinical routine.Auditory steady state responses (ASSR) are a promising tool to overcome the above mentioned limitations. ASSR can be analysed in the spectral domain with powerful statistical tests. From a clinical perspective, it is useful that ASSR can be recorded for up to four frequencies and in both ears simultaneously. Commercial implementations were already successfully used in some clinics for the past few years. The limitation of this method is, so far, that the recordings are fairly time consuming. This may be overcome by an optimal choice of the stimuli and recording parameters. The aim of the present study is to investigate the impact of stimulus and recording parameters on ASSR for the clinically highly relevant stimulus type chirp in a multi-frequency setting. The chirp compensates for the delay of the traveling wave in the cochlea and thus produces large AEP response amplitudes. Although chirp-evoked ASSR are already used in the clinic, data on the influence of basic stimulus and recording parameters on chirp-evoked ASSR are not yet available. The multi-frequency chirp-evoked ASSR with optimised parameters may be the final step towards an objective assessment of frequency-specific thresholds in quiet in a clinic. The impact of stimulus and recording parameters is investigated in adult normal-hearing listeners and participants with a sensorineural hearing loss. These data are used as a basis for the optimisation of the parameters for a robust and efficient clinical ASSR recording.