Moore B C, Alcántara J I, Stone M A, Glasberg B R
Department of Experimental Psychology, University of Cambridge.
Br J Audiol. 1999 Jun;33(3):157-70. doi: 10.3109/03005369909090095.
A model for predicting loudness for people with cochlear hearing loss was applied to the problem of the initial fitting of a multi-channel compression hearing aid. The fitting was based on two constraints: (1) The specific loudness pattern evoked by speech of a moderate level (65 dB SPL) should be reasonably flat (equal loudness per critical band), and the overall loudness should be similar to that evoked in a normal listener by 65-dB speech (about 23 sones for binaural listening); (2) Speech with an overall level of 45 dB SPL should just be audible in all frequency bands from 500 Hz up to about 4 kHz, provided that this does not require compression ratios exceeding about 3. These two constraints were used to determine initial values for the gain, compression ratio and compression threshold in each channel of a multi-channel compression system. This initial fitting was based entirely on audiometric thresholds; it does not require suprathreshold loudness measures. The fitting method was evaluated using an experimental fast-acting four-channel compression system. The initial fitting was followed by an adaptive procedure to 'fine tune' the fitting, and the aids were then used in everyday life. Performance was evaluated by use of questionnaires and by measures of speech intelligibility. Although the fine tuning resulted in modest changes in the fitting parameters for some subjects, on average the frequency response shapes and compression ratios were similar before and after the fine tuning. The fittings led to satisfactory loudness impressions in everyday life and to high speech intelligibility over a wide range of levels. It was concluded that the initial fitting method gives reasonable starting values for the fine tuning.
一种用于预测人工耳蜗听力损失患者响度的模型被应用于多通道压缩式助听器的初始验配问题。验配基于两个约束条件：（1）中等强度语音（65 dB声压级）诱发的特定响度模式应相当平坦（每个临界带宽内响度相等），且总体响度应与正常听力者在65 dB语音刺激下诱发的响度相似（双耳聆听时约为23宋）；（2）总体声压级为45 dB的语音在500 Hz至约4 kHz的所有频段应刚好可听，前提是这不需要压缩比超过约3。这两个约束条件用于确定多通道压缩系统每个通道中增益、压缩比和压缩阈值的初始值。这种初始验配完全基于听力阈值；不需要阈上响度测量。使用实验性快速作用四通道压缩系统对验配方法进行了评估。初始验配后采用自适应程序对验配进行“微调”，然后将助听器用于日常生活。通过问卷调查和语音清晰度测量来评估性能。尽管微调导致一些受试者的验配参数有适度变化，但平均而言，微调前后频率响应形状和压缩比相似。这些验配在日常生活中带来了令人满意的响度感受，并在很宽的声压级范围内实现了高语音清晰度。得出的结论是，初始验配方法为微调提供了合理的起始值。
