Source-Filter Interaction in Speech

描述(申请人提供)：这项研究致力于改进存在了半个多世纪的言语产生理论，即源过滤理论。它通常用于声学语音学以及描述语音和言语障碍。它还被广泛用于语音处理，以将声源与声谐振器分开。语音产生研究的最新进展，主要是通过计算机模拟，已经表明喉部的主要声源(声门气流)可以受到从声道向后传播到喉部的声压的高度影响。反馈相互作用会干扰声带振动，产生基音跳跃、亚谐频率，甚至是混沌。它还会影响发声阈值压力，使其更容易或更难自我维持声带振荡。这项研究的意义在于，某些声音质量，通常被标记为嗓音障碍，可能是人类声音正常清单的一部分。具体目标是(1)确定声源-滤光器相互作用(SFI)是否会影响声音强度，(2)发现哪些声道构型导致最大的相互作用，(3)验证或使被称为逆滤波的过程无效，据称 将源特征与滤波特征分离，以及(4)确定老化男性嗓音中的发声不稳定是否与SFI有关。人类志愿者和计算机模拟将以结构化的方式被用来量化和解释SFI的性质。

DESCRIPTION (provided by applicant): This research addresses refinement of a theory of speech production that has existed for more than half a century, the source-filter theory. It is used routinely in acoustic phonetics and in the description of voice and speech disorders. It is also used extensively in speech processing to separate sound sources from sound resonators. Recent advances in speech production research, primarily with computer simulation, have shown that the primary sound source in the larynx (glottal airflow) can be highly influenced by acoustic pressures propagating backwards from the vocal tract to the larynx. The feedback interaction can disturb vocal fold vibration, producing pitch jumps, subharmonic frequencies, or even chaos. It can also affect the phonation threshold pressure, making it either more easy or more difficult to self-sustain vocal fold oscillation. The significance of the research is that cerain vocal sound qualities, often labeled as voice disorders, may be part of a normal inventory of human sounds. Specific aims are (1) to determine if vocal intensity can be affected by source-filter interaction (SFI), (2) to discover which vocal tract configurations lead to the greatest interactions, (3) to validate or invalidate a procedure known as inverse-filtering, which allegedly separates the source characteristics from filter characteristics, and (4) to determine if vocal instabilities in the aging male voice are related to SFI. Human volunteers and computer simulation will be used in a structured way to quantify and explain the nature of SFI.