Tracing the mechanisms that generate tonal content in voiced speech

声音障碍具有高度的社会和经济相关性，因为它影响着我们社会中的许多人。健康人的正常嗓音是复杂的流体-结构-声学相互作用的结果。声带的结构运动强烈地调节通过声门的气流，声门产生声音的主要部分。因此，正常和健康的发声的特征在于强谐波含量。声带下游的声道是声带运动和气流声反馈耦合的关键因素。因此，除了创建共振峰之外，我们假设声道还影响所产生的语音信号中的高次谐波的生成，这对于健康的声音至关重要。该研究项目的中心目标是基于对基本机制的完全耦合实验研究，推进对发声过程中音调声音产生的理解。在我们的实验室的实验装置复制了一个完善的喉模型的完全耦合发声过程。我们的目标是进一步扩展其功能，通过整合几何可变的简化通道，以及基于MRI的声道形状的实验。这使我们能够分别研究发声过程中受声道影响的不同机制。该项目包括三个创新方面。(1)重点是设置在谐波含量和声学的回耦合在一个完全耦合的实验方法，代表发声过程的基本机制。(2)利用我们最先进的PIV技术，可以直接通过实验确定声源场和声辐射。(3)通过激光测振仪测量声带运动及其结构的相互作用，并重点关注其谐波含量，以及产生的综合描述。最后，这产生了负责谐波声音产生的机制，它与声道的反馈耦合相互作用。

Voice disorders are of high social and economic relevance as it affects many people in our society. Consequently, concerned patients suffer from increased physiological and psychological stress as reduced quality of life.The normal voice of a healthy human is the result of a complex fluid-structure-acoustic interaction. The structural motion of the vocal folds intensely modulates the flow through the glottis, which generates the main portion of the sound. Thereby, normal and healthy phonation is characterized by a strong harmonic content. The vocal tract downstream of the vocal folds is a key factor for acoustic back-coupling on the vocal fold motion as well as the flow. Hence, in addition to creating formants, we hypothesize that the vocal tract also impacts the generation of higher harmonics in the resulting voice signal, which is crucial for a healthy voice. The central objective of the research project is to advance the understanding of tonal sound generation during phonation based on a fully-coupled experimental investigation of the underlying mechanisms. The experimental setup in our laboratory replicates the fully-coupled phonation process in a well-established larynx model. We aim to further extend its functionality by integrating geometry-variable simplified channels as well as an MRI-based vocal tract shape for experiments. This enables us to separately investigate the different mechanisms during phonation as influenced by a vocal tract. The project incorporates three innovative aspects. (1) The focus is set on the harmonic content and acoustic back-coupling in a fully-coupled experimental approach that represents the basic mechanisms of the phonatory process. (2) With our state-of-the-art PIV-based technique, a direct experimental determination of the acoustic source field and sound radiation is enabled. (3) A comprehensive description of the vocal fold motion and its structure interaction is generated by laser vibrometer measurements with a strong focus on its harmonic content, as well.Finally, this yields the mechanisms responsible for harmonic sound generation, which interacts with back-coupling of the vocal tract.