Mechanisms of sound localization investigated with head-related transfer functions

用头部相关传递函数研究声音定位机制

• 批准号: 280063511
• 负责人: Professor Dr. Hartmut Führ
• 金额: --
• 依托单位: Lehrstuhl A für Mathematik (Analysis und Zahlentheorie)
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2018-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/280063511?language=en
• 关键词: Mechanisms; sound; localization; investigated; head

Sound-localization behavior is an important orienting reaction of humans and animals that serves to fixate interesting objects. The barn owl is a model system for sound localization because of the nocturnal ecological niche it occupies. This led to adaptations that allow the barn owl to hunt mainly by listening. Many mechanisms underlying sound localization have been worked out through work in the barn owl. So far experimental approaches have used single stimulus parameters. Such experiments showed that the interaural time difference plays the main role in azimuthal sound localization, while the interaural level difference is important for elevational sound localization. However, these experiments have also suggested that further, hitherto unknown cues influence sound-localization behavior and the responses of neurons extracting sound-localization information. It specifically remains unclear whether and how positions in space may be disambiguated that have equal broadband interaural time and level differences. To tackle such questions we propose a new approach, using head-related transfer functions (HRTFs) for stimulation. The HRTF recorded at the eardrum contains the information originating from one position in space, albeit distorted by the body, head, and the outer-ear of the listener. HRTFs should, thus, contain the most complete information a listener can use in sound localization. We propose a close interaction of theory and experiment, proceeding in five steps: 1) record HRTFs, 2) analyze the HRTFs and find out whether the position where the HRTF was recorded can be reconstructed by reverse modelling, 3) use normal and manipulated HRTF-stimuli in behavioral experiments to find out which information contained in the HRTF is used by the animal and how, 4) use HRTF-stimuli in electrophysiological recordings to find out which information drives the spiking responses, and 5) use the spiking responses to try to reconstruct the position of the source that elicited a given response. We expect that the new procedures and results will significantly advance our understanding of sound localization, not only in the barn owl, but also in other animals, including humans. Our studies may also yield results that may be implemented in sound-localizing systems, like autonomic agents.

声音定位行为是人类和动物的一种重要的定向反应，用于固定感兴趣的物体。仓鸮是声音定位的模型系统，因为它占据了夜间生态位。这导致了仓鸮主要通过倾听来狩猎的适应。通过对仓鸮的研究，人们已经发现了许多声音定位的机制。到目前为止，实验方法使用单一刺激参数。实验结果表明，两耳时差对方位角声定位起主要作用，而两耳声级差对仰角声定位起重要作用。然而，这些实验还表明，迄今为止未知的线索会进一步影响声音定位行为和提取声音定位信息的神经元的反应。具体来说，目前还不清楚是否以及如何消除空间位置的歧义，这些位置具有相等的宽带耳间时间和水平差异。为了解决这些问题，我们提出了一种新的方法，使用头部相关的传递函数（HRTF）的刺激。在鼓膜处记录的HRTF包含源自空间中的一个位置的信息，尽管被收听者的身体、头部和外耳扭曲。因此，HRTF应该包含收听者在声音定位中可以使用的最完整的信息。我们提出了理论与实验的密切互动，分为五个步骤：1）记录HRTF，2）分析HRTF并找出记录HRTF的位置是否可以通过反向建模重建，3）在行为实验中使用正常和操纵的HRTF刺激以找出动物使用HRTF中包含的哪些信息以及如何使用，4）在电生理记录中使用HRTF刺激来找出哪些信息驱动尖峰响应，以及5）使用尖峰响应来尝试重建引起给定响应的源的位置。我们希望新的程序和结果将显着推进我们对声音定位的理解，不仅在仓鸮，而且在其他动物，包括人类。我们的研究也可能产生可以在声音定位系统中实现的结果，如自主代理。