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，这些研究将提供关于内耳在没有任何外部声音的情况下如何产生声音的新知识。这些被称为自发耳声发射。由于内耳毛细胞的主动反馈，听力正常的人可以检测到微弱的声音。自发的耳声发射是这种反馈的直接结果。这些排放通常是在人类和其他物种中测量的，但仍然知之甚少。该项目专注于基础研究，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。通过提高对耳朵的了解，该项目最终将有助于更好地诊断和治疗听力损失，这将造福美国社会。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。该项目将帮助代表不足的群体更广泛地参与研究，对工程教育产生积极影响，并使学生对过度暴露噪音的风险和后果敏感。自发耳声发射(SOAE)提供了关于内耳如何运作的重要线索，因为它暗示耳朵是一个活跃的系统。然而，目前对于SOAE的产生存在两种似乎不可调和的理论，即驻波(SW)模型和耦合极限环振子(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，当考虑外部刺激和噪声对国有企业的影响时，两种理论预测的非线性动力学明显不同。为了验证这一假设，研究团队将为西南偏南理论和CLCO理论实施一系列复杂程度不同的模型。这些模型将被用来研究(1)SOAE的产生机制；(2)外部音调和噪声(内部和外部)对SOAE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(S)。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的智力优势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.