Neural Pathophysiology and Suprathreshold Processing in Young Adults with Normal Thresholds

阈值正常的年轻人的神经病理生理学和阈上处理

• 批准号: 9362741
• 负责人: Stéphane Maison
• 金额: $ 56.44万
• 依托单位: MASSACHUSETTS EYE AND EAR INFIRMARY
• 依托单位国家: 美国
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-02 至 2022-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9362741
• 关键词: Acoustic Nerve; Acoustics; Adult; Affect; Age; Animals; Audiometry; Auditory; Auditory Brainstem Responses; Binaural; Cluster Analysis; Cochlea; Cochlear Nerve; Diagnosis; Diagnostic; Diffuse; Disabled Persons; Dose; Ear; Elements; Enrollment; Environment; Formulation; Frequencies; Functional disorder; Generations; Hair Cells; Hearing; Human; Hyperacusis; Impairment; Laboratories; Labyrinth; Life Style; Longitudinal Studies; Loudness; Measures; Medial; Music; Nerve Degeneration; Nerve Fibers; Nerve Regeneration; Neurons; Neuropathy; Noise; Outcome; Outcome Measure; Patient Self-Report; Performance; Peripheral; Physiological; Pilot Projects; Presbycusis; Prevalence; Principal Component Analysis; Protective Devices; Psychophysics; Public Health; Public Policy; Questionnaires; Recording of previous events; Recruitment Activity; Reflex action; Risk; Sensorineural Hearing Loss; Severities; Speech; Statistical Models; Structure; Students; Synapses; Testing; Therapeutic; Time; Tinnitus; Translating; Variant; Work; auditory processing; base; cell injury; cohort; college; dosimetry; ear muscle; experimental study; ganglion cell; hearing impairment; insight; middle ear; otoacoustic emission; outcome prediction; programs; public health relevance; rehearsal; relating to nervous system; repaired; response; sound; speech recognition; spiral ganglion; theories; university student; young adult

Project 3 Summary – Abstract Recent animal work from our laboratories suggests that the synapses between hair cells and cochlear nerve terminals are the most vulnerable elements of the inner ear in both noise-induced and age-related hearing loss. This synaptic degeneration does not affect hair cells or thresholds and, therefore, hides behind a normal audiogram. However, this “hidden hearing loss” likely contributes to decreased ability to understand speech, especially in noisy environments. It may also be an underlying cause of tinnitus and hyperacusis. In animals, hidden hearing loss can be diagnosed by measuring the suprathreshold amplitude of ABR wave I, the sound-evoked activity of the cochlear nerve. We have begun translating these insights from animal work to human studies. We have a pilot study from audiometrically normal young adults showing significant correlations between electrocochleographic measures consistent with cochlear synaptopathy and performance on difficult speech recognition tasks. Here we propose to extend our pilot study into large-scale cross-sectional (Aim 1) and longitudinal (Aim 2) studies of hidden hearing loss in college students with normal audiometric thresholds and widely differing lifestyle with respect to aural abuse, as quantified by questionnaire. For Aim 1, we will test the hypotheses that hidden hearing loss, defined as performance deficits on difficult word- recognition tasks, is correlated with physiologic response deficits consistent with cochlear synaptopathy and with estimated lifetime noise dose. Our outcome measures will be speech-in-noise tests. A statistical model will test the correlation of these outcomes with noise-exposure history and with a battery of physiological or psychophysical measures chosen to probe different stages of auditory processing, i.e. distortion product otoacoustic emissions and high-frequency audiometry, SP/AP ratio and envelope following responses to tones at high modulation frequencies, middle ear muscle or medial olivocochlear reflexes, several variants of frequency following response probing monaural and binaural temporal fine-structure processing, a temporal integration test of theories on stochastic undersampling in cochlear synaptopathy, and tinnitus severity/handicap and loudness discomfort level/hyperacusis. Using principal components analysis, cluster analysis and adaptive LASSO, we will find the test combination that best predicts the outcome measures and assess the relative contributions of peripheral vs. central pathophysiology to the observed performance deficits. In Aim 2, we will test the hypothesis that hidden hearing loss progresses in young adults with regular and continued acoustic overexposure by tracking a cohort of students over the five-year period of this project using the same test battery as described in Aim 2.

项目3摘要-摘要