Boys Town National Research Hospital, Omaha, Nebraska, USA.
Department of Special Education and Communication Disorders, University of Nebraska-Lincoln, Lincoln, Nebraska, USA.
Ear Hear. 2019 Jan/Feb;40(1):143-155. doi: 10.1097/AUD.0000000000000603.
The primary aim of this study is to describe the effect of hearing aid amplification on the contribution of specific frequency bands to overall loudness in adult listeners with sensorineural hearing loss (SNHL). Results for listeners with SNHL were compared with results for listeners with normal hearing (NH) to evaluate whether amplification restores the normal perception of loudness for broadband sound. A secondary aim of this study is to determine whether the loudness perception of new hearing aid users becomes closer to normal over the first few months of hearing aid use. It was hypothesized that amplification would cause the high-frequency bands to contribute most to the perception of loudness and that this effect might decrease as new hearing aid users adapt to amplification.
In experiment 1, 8 adult listeners with SNHL completed a two-interval forced-choice loudness task in unaided and aided conditions. A control group of 7 listeners with NH completed the task in the unaided condition only. Stimuli were composed of seven summed noise bands whose levels were independently adjusted between presentations. During a trial, two stimuli were presented, and listeners determined the louder one. The correlation between the difference in levels for a given noise band on every trial and the listener's response was calculated. The resulting measure is termed the perceptual weight because it provides an estimate of the relative contribution of a given frequency region to overall loudness. In experiment 2, a separate group of 6 new hearing aid users repeated identical procedures on 2 sessions separated by 12 weeks.
Results for listeners with SNHL were similar in experiments 1 and 2. In the unaided condition, perceptual weights were greatest for the low-frequency bands. In the aided condition, perceptual weights were greatest for the high-frequency bands. On average, the aided perceptual weights for listeners with SNHL for high-frequency bands were greater than the unaided weights for listeners with NH. In experiment 2, hearing aid experience did not have a significant effect on perceptual weights.
The high frequencies seem to dominate loudness perception in listeners with SNHL using hearing aids as they do in listeners with NH. However, the results suggest that amplification causes high frequencies to have a larger contribution to overall loudness compared with listeners with NH. The contribution of the high frequencies to loudness did not change after an acclimatization period for the first-time hearing aid users.
本研究的主要目的是描述在患有感音神经性听力损失（SNHL）的成年听力障碍者中，助听器放大对特定频带对整体响度贡献的影响。将 SNHL 听力障碍者的结果与正常听力（NH）听力障碍者的结果进行比较，以评估助听器是否恢复了宽带声音的正常响度感知。本研究的次要目的是确定新使用助听器的听力障碍者的响度感知是否在使用助听器的头几个月内变得更加正常。研究假设放大将导致高频带对响度感知的贡献最大，并且随着新使用助听器的听力障碍者适应放大，这种影响可能会减小。
在实验 1 中，8 名患有 SNHL 的成年听力障碍者在未助听和助听条件下完成了两次间隔强迫选择响度任务。一组 7 名 NH 听力障碍者仅在未助听条件下完成了任务。刺激由七个求和噪声带组成，这些带的电平在呈现之间独立调整。在一次试验中，呈现两个刺激，然后听力障碍者判断哪个更响亮。计算每个试验中给定噪声带的电平差异与听力障碍者反应之间的相关性。由此得到的度量值称为感知权重，因为它提供了给定频率区域对整体响度的相对贡献的估计。在实验 2 中，一组 6 名新使用助听器的听力障碍者在 12 周的间隔后重复了相同的程序。
实验 1 和 2 中 SNHL 听力障碍者的结果相似。在未助听条件下，低频带的感知权重最大。在助听条件下，高频带的感知权重最大。平均而言，SNHL 听力障碍者的助听高频带感知权重大于 NH 听力障碍者的未助听权重。在实验 2 中，助听器使用经验对感知权重没有显著影响。
使用助听器的 SNHL 听力障碍者的高频似乎像 NH 听力障碍者一样主导响度感知。然而，结果表明，与 NH 听力障碍者相比，放大会导致高频对整体响度的贡献更大。对于初次使用助听器的听力障碍者，在适应期后，高频对响度的贡献没有变化。
