Complex Pitch Perception in Complex Environments

描述（由申请人提供）：该项目的长期目标是进一步了解听觉系统如何形成音高感知，以及音高或基频如何用于分离来自不同来源的声音。该项目有3个主要目标，所有这些都将联合收割机心理物理实验与计算建模相结合。第一个目的是阐明如何在正常和受损的听力编码的单谐波复杂的声音的音高。我们假设，减少可用性的解决谐波，结合减少个别谐波的编码精度，可以预测许多困难的听力受损的听众在更复杂的声学环境。第二个目标是继续寻找我们感知多个音高和在其他竞争复合体存在下听到一个音高的能力的机制。通过研究仔细控制的情况下，刺激要么完全重叠的频谱或不重叠，在所有，我们能够控制的程度，其中个别谐波内的复杂的解决。这些情况充当更复杂情况的模型，其中多个部分重叠的声音联合收割机组合以形成我们的日常声学环境。第三个目标采取了更实用的方法，通过检查音高和基频在语音和音乐感知中的作用。使用耳蜗植入处理的模拟，我们将阐明在残余听力（声加电刺激）的条件下提供益处的机制，并评估该益处可归因于改善音高信息的程度。我们还将开始系统分析日常声学情况下分辨谐波的存在（或缺乏），例如在竞争性谈话者在场的情况下的讲话和小型合奏中的音乐。来自这些分析的数据将为复杂音高感知的模型提供强有力的约束，这些模型在不同程度上依赖于分辨谐波的存在。了解音高是如何编码和利用在正常和受损的听觉系统应具有重要意义的设计和开发的听觉假体，如人工耳蜗植入，并在自动语音识别系统的源分离算法。

DESCRIPTION (provided by applicant): The long-term goal of this project is to further our understanding of how the auditory system forms pitch percepts and how pitch or fundamental frequency is used to separate sounds coming from different sources. The project has 3 main aims, all of which combine psychophysical experiments with computational modeling. The first aim is to elucidate how the pitch of single harmonic complex sounds is coded in normal and impaired hearing. We hypothesize that the reduced availability of resolved harmonics, in conjunction with a reduction in the coding accuracy of individual harmonics, can predict many difficulties experienced by hearing-impaired listeners in more complex acoustic environments. The second aim is to continue our search for the mechanisms underlying our ability to perceive multiple pitches and to hear out 1 pitch in the presence of other competing complexes. By studying carefully controlled situations where the stimuli either completely overlap in spectrum or do not overlap at all, we are able to control the degree to which individual harmonics within the complexes are resolved. These situations serve as models for the more complex situations, where multiple partially-overlapping sounds combine to form our everyday acoustic environment. The third aim takes a more applied approach by examining the role of pitch and fundamental frequency in speech and music perception. Using simulations of cochlear-implant processing we will elucidate the mechanisms involved in providing a benefit under conditions of residual hearing (acoustic plus electric stimulation) and assess the degree to which the benefit can be ascribed to improved pitch information. We will also begin a systematic analysis of the presence (or lack thereof) of resolved harmonics in everyday acoustic situations, such as speech in the presence of competing talkers and music in small ensembles. The data from these analyses will provide strong constraints for models of complex pitch perception that rely to varying degrees on the presence of resolved harmonics. Understanding how pitch is coded and utilized in the normal and impaired auditory system should have important implications for the design and development of auditory prostheses, such as cochlear implants, and for source segregation algorithms within automatic speech recognition systems.