Mechanism for Producing Complex Sounds

描述（由申请人提供）：我们提出的研究目标是了解复杂声音的产生机制，这些声音可以在许多鸟类的歌声中找到，并揭示外围系统在这一过程中的作用。作为第一步，生理参数（注射肌肌电图，气管和支气管气流数据）将描述三种物种，斑胸草雀，棕头牛鹂和欧洲椋鸟的歌声的全范围声学特征。基于这些数据，将开发和实验测试鸟类发声器官鸣管的声音产生模型，以阐明这种声音多功能性背后的物理过程。按照这种综合方法，重点将放在非平凡的声学特征上，这些特征存在于选定物种的歌曲中。这些鸟的注射器肌肉的肌电图记录将揭示神经指令在多大程度上可以解释复杂声音的产生。我们将通过建模和实验测试相结合的方法来验证复杂声音是由鸣管两个声源之间的声学相互作用和反馈压力对唇部振动产生的假设。本研究为揭示鸟类鸣叫产生的外围物理机制提供了一种综合的方法。研究结果将告诉我们，在神经控制没有平行复杂性的情况下，外围系统能在多大程度上产生复杂的声学行为。这项研究将为鸟类的神经控制、外周相互作用和习得发声行为之间的联系提供有价值的见解，因此，探索对我们理解人类语言产生和运动控制也有意义的问题。

DESCRIPTION (provided by applicant): The goal of our proposed research is to understand the mechanisms involved in the generation of complex sounds, which can be found in the songs of many birds, and to unveil the role of the peripheral system in this process. As an initial step, the physiological parameters (electromyograms of syringeal muscles, tracheal and bronchial airflow data) will be described for the full range of acoustic characteristics in the songs of three species, zebra finch, brown-headed cowbird and European starling. Based on these data, models of sound generation in the avian vocal organ, the syrinx, will be developed and experimentally tested in order to elucidate the physical processes underlying this acoustic versatility. Following this integrated approach, the focus will be on nontrivial acoustic features, which are present in the songs of the selected species. Electromyographic recordings of syringeal muscles in these birds will reveal the degree to which neural instructions can account for the generation of complex sounds. We will test the hypotheses that complex sounds arise from acoustic interaction between the two sound sources of the syrinx and from feedback pressure onto labial vibration by a combination of modeling and experimental tests. The proposed research is a comprehensive integrative approach to illuminate the peripheral physical mechanisms of birdsong production. The results will inform about the degree to which the peripheral system can give rise to complex acoustic behavior without parallel complexity in the neural control. This research will provide valuable insight into the link between neural control, peripheral interactions and learned vocal behavior in birds and, therefore, explore issues that are also of significance for our understanding of human speech production and motor control.