仿生主动降噪的听觉原理

Auditory mechanisms of bionic active noise reduction

噪声暴露除会导致噪声性耳聋外,还会导致神经、血管、消化等多种系统的功能紊乱和精神障碍等。社会的高速发展和现代化为噪声防护带来了巨大挑战。对噪声的防护最有效和根本性的方法是控制和消除噪声源。对于进入听觉系统的声音,一方面通过已被广泛接受的主动放大机制对信号放大后便于获得更好的听觉,然而未被认识到的是,听觉系统对噪声也存在主动的减噪和抑制机制。我们认为听觉器官通过特定的相关结构、机制,阻止噪声进入听觉系统,提高了对外部信息的接收和处理能力。同时,对于阈值以上的足以引起听觉兴奋和信号传递的声音,主动降噪的机制将对其进行一定程度的衰减和抑制,达到保护听觉的目的。咽鼓管、中耳肌肉、圆窗、卵圆窗等结构可能对能量衰减有不同的贡献。作者首次提出听觉器官是完美的消声减噪器的新理论假说,同时深入阐述了仿生主动降噪的听觉原理,通过对耳组织及其相关精细结构的生物力学分析,有可能利用仿生学原理建立主动减震降噪新方法,这种创新思维将有希望突破噪声防控理论瓶颈,对聋病的防治具有颠覆性和突破性意义。

Noise exposure can lead to hearing loss as well as dysfunction of the central nervous, cardiovascular, digestion and endocrine systems. Severe noise exposure may also result in mental disorders or even decreased fertility. Various kinds of noise have been identified and bring great challenge to hearing protection. The most effective method to prevent noise-induced damage is to control or eliminate the noise source. Active noise reduction against the sound source may help meet the needs of rapid social development and modernization. It is known that the sound received by auditory system is magnified by the active cochlear amplifier during its transmission for enhanced audition; on the other hand what has not been well noticed is the active noise suppression and reduction by the auditory system. Based on clinical experiences and existing research data, we propose that, through certain structures and mechanisms, the hearing organ can enhance reception and processing of sound signals by increasing signal/noise ratio through limiting noise entrance. For the first time, we put forward a theory that hearing organ is a perfect noise eliminator and present a description of mechanisms of bionic active noise reduction. For example, while signals above the hearing threshold excite the hearing organ and start signal transmission, the middle ear attenuates loud sound by active suppression. By biomechanical analysis of relevant sophisticated structures within the hearing system, it is possible to establish new active noise reduction methods. This innovative thinking may break the bottleneck in noise protection and may have a revolutionary significance for prevention and treatment of hearing loss.