Cooperativity Between Hair Cells And Role Of Noise In The Spontaneous Generation Of Sounds By The Inner Ear

这笔赠款将支持研究，这将有助于新的知识，关于声音是如何产生的内耳在没有任何外部声音。这些被称为自发耳声发射。 听力正常的人可以检测到微弱的声音，这是由于内耳毛细胞的主动反馈。自发耳声发射是这种反馈的直接结果。 这些排放通常在人类和其他物种中测量，但仍然知之甚少。该项目侧重于基础研究，提供有关耳朵如何运作和产生自发辐射的必要知识。影响数百万美国人的听力障碍通常是由毛细胞功能丧失引起的。通过提高对耳朵的理解，该项目最终将有助于更好地诊断和治疗听力损失，这将使美国社会受益。该项目涉及多个学科，包括生物物理学，生物力学，计算建模，声学和非线性动力学。该项目将有助于扩大代表性不足的群体参与研究，对工程教育产生积极影响，并使学生对噪音过度的风险和后果保持敏感。自发耳声发射（SOAE）提供了关于内耳如何运作的重要线索，因为它意味着耳朵是一个活跃的系统。然而，目前存在两个看似不可调和的理论产生SOAE，驻波（SW）模型和耦合极限环振荡器（CLCO）模型。该项目旨在通过评估这些理论预测实验SOAE记录的关键特征的能力来阐明SOAE产生的生物物理机制。 该项目的中心假设是，这两个理论预测显着不同的非线性动力学时，外界刺激和噪声的SOAE的影响被认为是。 为了验证这一假设，研究小组将为SW和CLCO理论实施一系列不同复杂性的模型。这些模型将用于研究（1）SOAE的产生机制;（2）外部音调和噪声（内部和外部）对SOAE的非线性动力学的影响;（3）噪声和SOAE产生对低电平声音检测的功能后果。模型预测与实验SOAE测量的比较将用于评估模型的有效性，约束这些模型，并确定最佳模型。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This grant will support research that will contribute new knowledge regarding how sounds are generated by the inner ear in the absence of any external sound. These are called spontaneous otoacoustic emissions. Humans with normal hearing can detect faint sounds due to the active feedback from hair cells within the inner ear. Spontaneous otoacoustic emissions are a direct consequence of this feedback. These emissions are commonly measured in humans and other species, but remain poorly understood. This project focuses on fundamental research that provides needed knowledge about how the ear operates and generates spontaneous emissions. Hearing impairment, which affects millions of Americans, is often caused by loss of hair cell function. By improving understanding of the ear, this project will ultimately help to better diagnose and treat hearing loss, which will benefit US society. This project involves multiple disciplines including biophysics, biomechanics, computational modeling, acoustics, and nonlinear dynamics. The project will help broaden participation of underrepresented groups in research, positively impact engineering education, and sensitize students to the risks and consequences of noise overexposure. Spontaneous otoacoustic emissions (SOAEs) provide important clues about how the inner ear operates because it implies that the ear is an active system. However, two seemingly irreconcilable theories currently exist for SOAE generation, the standing wave (SW) model and the coupled limit-cycle oscillator (CLCO) model. This project aims to clarify the biophysical mechanisms of SOAE generation by evaluating the ability of these theories to predict the key characteristics of experimental SOAE recordings. The central hypothesis of this project is that the two theories predict significantly different nonlinear dynamics when the effect of external stimuli and noise on SOAEs is considered. To test this hypothesis, the research team will implement a series of models of varying complexity for the SW and CLCO theories. These models will be used to investigate (1) the generation mechanisms of SOAEs; (2) the effect of external tones and noise (both internal and external) on the nonlinear dynamics of SOAEs; (3) the functional consequences of noise and SOAE generation on the detection of low-level sounds. Comparison of model predictions to experimental SOAE measurements will be used to assess the validity of the models, constrain these models, and identify the best model(s).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.