Mechanism for Producing Complex Sounds

描述(申请人提供)：我们提出的研究的目标是了解复杂声音的产生机制，这种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，将描述三个物种的歌声中的全部声学特征的生理参数(脊髓空洞肌肉肌电图、气管和支气管气流数据)，斑马雀、褐头牛鸟和欧洲八哥。基于这些数据，将开发鸟类发声器官--空洞的声音产生模型，并进行实验测试，以阐明这种声学多功能性背后的物理过程。按照这种综合方法，重点将放在重要的声学特征上，这些特征存在于选定物种的歌声中。这些鸟类的脊髓空洞肌的肌电记录将揭示神经指令在多大程度上能够解释复杂声音的产生。我们将通过模拟和实验测试相结合的方法来验证复杂声音是由空洞的两个声源之间的声学相互作用和对唇部振动的反馈压力产生的假设。提出的研究是一种全面的综合方法，以阐明鸟鸣产生的外围物理机制。结果将告知，在神经控制中，外围系统可以在多大程度上引起复杂的声学行为，而不会产生平行的复杂性。这项研究将对鸟类的神经控制、外周相互作用和获得性发声行为之间的联系提供有价值的见解，从而探索对我们理解人类言语产生和运动控制也具有重要意义的问题。

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.