Acoustic correlates of phonetic perception

如果我们对这一问题有更深的认识，就可以解决许多实际和理论问题。 语音识别的听觉和知觉机制。这一点的实际应用 知识包括人工耳蜗信号处理器的改进，语音的改进 合成设备，稳健语音识别算法的发展，以及训练的发展 听力受损的扬声器设备。拟议中的实验分为三大类。一个 设计了一系列广泛的实验来测试一种新的元音感知模型的有效性 在前一批赠款期间开发的。该模型假定元音标识由 模板匹配过程，包括将窄带输入光谱与一组平滑的 频谱形状的模板是通过普通的语音接触学习的。进行的评估 在前一个授权期内，该模型能够从大的元音识别元音， 多人通话数据库，精确度接近人类听众。我们想把这条线延伸到 致力于解决以下问题：(1)对时间和光谱线索与元音识别的集成进行建模， (2)检验理论对语音环境、信号等因素变化的稳健性 周期性和谱形特征，如共振峰幅度关系，以及(3)结合 心理上看似合理的归一化方案，可能解释了听众识别的能力 具有不同声道特征的说话者的讲话。将运行第二组实验， 测量通过语音信号传递给听众的语音信息有多少 由专门设计的语音合成算法生成，该算法仅保留了 原始语音信号，同时故意删除或扭曲其他提示。结果将允许推断 了解调节语音识别的潜在光谱表征的性质。一个 第三项工作是评估一种新的听觉频率分析理论。 在之前的授权期内。该理论假设听觉频谱不是在 但通过对听神经放电模式的分析，发现其位于中枢神经系统。一款软件 将开发模拟以用于测试该理论的有效性。

Numerous practical and theoretical problems could be addressed if we had a deeper understanding of the auditory and perceptual mechanisms underlying phonetic recognition. Practical applications of this knowledge include improvements to cochlear implant signal processors, the improvement of speech synthesis devices, the development of robust speech recognition algorithms, and the development of training devices for hearing-impaired speakers. The proposed experiments fall into three major categories. An extensive series of experiments is designed to test the validity of a new model of vowel perception that was developed during the previous grant period. The model assumes that vowel identity is recognized by a template-matching process involving the comparison of narrow band input spectra with a set of smoothed spectral-shape templates that are learned through ordinary exposure to speech. An evaluation conducted during the previous grant period showed that the model is capable of recognizing vowels from a large, multitalker database with accuracy approaching that of human listeners. We would like to extend this line of work to address issues such as: (1) modeling the integration of temporal and spectral cues to vowel identity, (2) testing the robustness of the theory to variation in factors such as phonetic environment, signal periodicity, and spectral shape feaures such as formant amplitude relations, and (3) incorporation of a psychologically plausible normalization scheme that might account for the ability of listeners to recognize speech from talkers with diverse vocal-tract characteristics. A second set of experiments will be run which measure how much phonetic information is transmitted to listeners by speech signals that have been generated by specially designed speech synthesis algorithms that preserve only some characteristics of the original speech signal, while purposely removing or distorting other cues. The results will allow inferences to be drawn about the nature of the underlying spectral representations that mediate phonetic recognition. A third line of work is designed to evaluate a new theory of auditory frequency analysis that was developed during the previous grant period. The theory assumes that the auditory spectrum is calculated not at the periphery but in the central nervous system through an analysis of auditory nerve firing patterns. A software simulation will be developed for use in testing the validity of the theory.