Magnusson L, Karlsson M, Leijon A
Department of Audiology, Sahlgrenska University Hospital, Göteborg, Sweden.
Ear Hear. 2001 Feb;22(1):46-57. doi: 10.1097/00003446-200102000-00005.
The purpose of this study was to investigate the applicability of the Speech Intelligibility Index (SII) in hearing aid fitting. It was hypothesized that estimated speech intelligibility, based on the SII, could be a more reliable measure than real speech recognition results for comparing hearing aid characteristics.
The test subjects were 29 elderly persons (66 to 80 yr) with mild-to-moderate hearing loss, who were using monaurally fitted linear hearing aids. They were selected from the files at Sahlgrenska hearing clinic. Speech recognition scores were obtained at fixed speech-to-noise ratios with Phonemically Balanced (PB) words in speech-weighted noise and in low-frequency noise. A Just-Follow-Conversation (JFC) test was performed with connected speech presented in the same background noises. The subjects were tested without hearing aid and with their hearing aids set at three different frequency responses. Predicted speech recognition scores were calculated for each condition based on the SII, complemented with a correction for sensorineural hearing impairment. The calculations involved speech and noise spectra, pure tone thresholds and insertion gain responses.
For each condition, the measured speech recognition scores were, on average, well predicted by the calculated scores. The intra-individual standard deviation of the predicted scores was estimated to be about one percent unit. The group results of the JFC test were in agreement with the word recognition results for the aided conditions, but a floor effect was observed for the unaided conditions.
Speech intelligibility prediction based on the modified SII is a valid estimate of speech recognition performance of hearing-impaired persons with mild-to-moderate hearing loss. Estimated intelligibility based on the SII is more reliable than actually measured speech recognition performance, for comparing amplification conditions within subjects.
本研究旨在探讨言语可懂度指数（SII）在助听器验配中的适用性。研究假设，基于SII估计的言语可懂度，在比较助听器特性时，可能比实际言语识别结果更可靠。
测试对象为29名年龄在66至80岁之间、患有轻至中度听力损失的老年人，他们单耳佩戴线性助听器。这些受试者从萨尔格伦斯卡听力诊所的档案中选取。在言语加权噪声和低频噪声中，以固定的言语噪声比，用音素平衡（PB）词汇获得言语识别分数。在相同背景噪声下呈现连贯言语，进行即听即答（JFC）测试。对受试者在不佩戴助听器以及助听器设置为三种不同频率响应的情况下进行测试。基于SII为每种情况计算预测的言语识别分数，并辅以对感音神经性听力损伤的校正。计算涉及言语和噪声频谱、纯音阈值和插入增益响应。
对于每种情况，计算得到的分数平均能很好地预测实测的言语识别分数。预测分数的个体内标准差估计约为1个百分点。JFC测试的组结果与助听条件下的单词识别结果一致，但在未助听条件下观察到了地板效应。
基于改良SII的言语可懂度预测是对轻至中度听力损失的听力障碍者言语识别性能的有效估计。在比较受试者内部的放大条件时，基于SII估计的可懂度比实际测量的言语识别性能更可靠。
