Intensity DLs and Masking in Normal and Impaired Hearing

这项工作的长期目标是了解听觉系统，以便对听力正常和听力损失的听者的音调、噪音和语音的感知进行建模。在这个项目中要测试的最重要的假设是，耳蜗性听力损失在不同的频率上以不同的方式改变听觉处理，并且在特定频率上的改变只会影响该频率附近的语音频带所传输的语音信息。为此，听力正常的听者和初级耳蜗源听力损失的听者将接受测试，以识别不同频谱方案下的听觉处理缺陷。这些缺陷将与听者通过应用新的语音识别灵敏度来理解噪声中的语音的能力有关。与传统的清晰度指数模型相反，SRS模型可以准确地预测语音在不相交频段上的清晰度，从而有可能对耳蜗声损失中的死区进行建模。它通过整合一个重要函数同余指数密度函数来预测语音的清晰度。CIDF跨越了语音的带宽。具体目的是检验四个假设：(1)语音识别性能可以从CIDF中预测出来，这取决于特定频率的心理声学能力。(2)正常听者的CIDF与语音清晰度指数中无意义音节的频带重要性函数相似。(3)在不同频段内随机改变信噪比得到的单刺激条件(COSS)函数不能反映每个频段对清晰度的贡献。相反，因为SRS模型可以通过改变反映语音的语言熵的单个参数来预测不同语音材料的识别性能。为了验证这些假设，通过新的COSS技术获得的CIDF将与针对时间、频率和强度处理的特定频率的心理声学测试的目标集的数据进行比较。SRS模型的预测将与测量的语音识别分数进行比较。所有实验的动机都是关于心理声学能力的模型预测或特定假设，这些能力可能对语音识别很重要。无论模型是否成功，数据都极有可能揭示对语音识别非常重要的听觉过程，并将显著增加我们对听力正常和听力损失听众的听觉感知和语音识别的理解。

The long-term objective of this work is to reach an understanding of the auditory system that will allow modeling of the perception of tones, noise, and speech in listeners with normal hearing and hearing losses. The overarching hypothesis to be tested in this project is that cochlear hearing losses alter auditory processing differently at different frequencies and that alterations at a specific frequency will affect only the speech information transmitted by a band of speech around that frequency. To this end, listeners with normal hearing and with hearing losses of primary cochlear origin will be tested to identify auditory- processing deficits in different spectral regimens. These deficits will be related to the listeners' abilities to understand speech in noise by applying the new Speech Recognition-Sensitivity. Contrary to traditional Articulation-Index models, the SRS model can accurately predict the intelligibility of speech in disjoint spectral bands, making it possible to model 'dead' regions in cochlear losses. It predicts speech intelligibility by, among other things, integrating an importance function the Congruence-Index Density Function. CIDF across the bandwidth of the speech. The specific aims are to test four hypotheses: (1) Speech - recognition performance can be predicted from the CIDF, which depends on frequency-specific psychoacoustic abilities. (2) The CIDF for normal listeners is similar to the band-importance function for nonsense syllables in the Speech Intelligibility Index. (3) Conditional-on-Single- Stimulus (COSS) functions obtained by varying the signal-to-noise ratio randomly in distinct frequency bands of speech do not reflect the contribution that each band makes to the intelligibility. Rather, as the SRS model can predict recognition performance for different speech materials by varying a single parameter that reflects the linguistic entropy of the speech. To test these hypotheses, the CIDF obtained with a new COSS techniques will be compared to data for a targeted set of frequency-specific psychoacoustical tests for temporal, frequency, and intensity processing. The SRS-model predictions will be compared to measured speech-recognition scores. All the experiments are motivated by model predictions or specific hypotheses about psychoacoustic abilities that are likely to be important for speech recognition. Regardless of the success of the model, are data are highly likely to reveal auditory processes that are important for recognition of speech and will add significantly to our understanding of auditory perception and speech recognition in listeners with normal hearing and with hearing losses.