Early Detection of Noise-Induced Hearing Loss

早期发现噪音引起的听力损失

• 批准号: 8857414
• 负责人: GLEN K. MARTIN
• 金额: --
• 依托单位: VA LOMA LINDA HEALTHCARE SYSTEM
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-01 至 2013-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8857414
• 关键词: Abbreviations; Adverse effects; Affect; American; Animals; Audiometry; Auditory Brainstem Responses; Award; Characteristics; Clinic; Clinical; Cochlea; Coin; Complex; Data; Development; Diagnosis; Ear; Early Diagnosis; Effectiveness; Excision; Exhibits; Exposure to; Frequencies; Funding; Generations; Goals; Grant; Hearing; Histopathology; Human; Human Resources; Impairment; Individual; Knowledge; Laboratories; Lead; Lesion; Life; Location; Maps; Masks; Measures; Methods; Military Personnel; Monitor; Noise; Noise-Induced Hearing Loss; Organ; Oryctolagus cuniculus; Patients; Pattern; Phase; Play; Procedures; Process; Protocols documentation; Recovery; Research; Research Personnel; Residual state; Sensory; Services; Signal Transduction; Simulate; Source; Specificity; Staging; Study Section; Suggestion; Sum; Techniques; Testing; Time; Veterans; Workplace; base; cochlear lesion; design; disability; follow-up; hearing impairment; improved; otoacoustic emission; prevent; research clinical testing; research study; response; sound; standard measure; vector

DESCRIPTION (provided by applicant): The overall goal of the proposed renewal application is to identify features of distortion product otoacoustic emissions (DPOAEs) that will eventually improve clinical methods for the early detection of noise-induced hearing loss (NIHL), which is a major sensory disability suffered by military veterans, in particular. Toward this end, two special-purpose DPOAE measures, which we have termed augmented and residual DP-grams, along with related DPOAE level/phase (L/P) maps will be obtained in rabbits before and after standardized noise- exposure episodes. These DP-grams will test the notion that subtle post-noise changes in the DPOAE response space can be more sensitively identified when the f2- and basal-source generated DPOAEs are isolated by the use of an interference tone (IT) and vector-subtraction methods than they can be by the common standard DP-gram. During our prior studies, we unexpectedly (see Preliminary Studies) discovered that rabbits, and likely other common laboratory species, do not have 'reflection emissions' arising from the DPOAE frequency place (fdp) as do humans. However, inexplicably, they still exhibit vertical phasing banding, which is a cardinal feature of reflection emissions. Using suppression methods to obtain DPOAE L/P maps with and without an IT placed at various frequency locations within the L/P space, the existence of a basal cochlear source of DPOAEs was established. This basal source was revealed as a residual DPOAE obtained as the vector difference between the 'with-IT' and 'without IT' DPOAE L/P maps. The term 'augmented' maps or DP- grams was coined to describe these frequency functions when obtained with the IT present in that, under this condition, the basal source that 'fills in' or 'masks' the true extent of the damage pattern is removed. The discovery of the contaminating basal source promises to modify the hearing field's current knowledge concerning the fundamental processes underlying DPOAE generation by the cochlea, and may also lead to the development of DPOAE tests that more sensitively identify the onset stages of NIHL. Such tests may also be useful in veterans, who are clinic patients, often with significant preexisting hearing losses, in that higher-level primary tones can be used to increase the signal-to-noise ratio (SNR), while maintaining the test's sensitivity and frequency specificity. Three specific aims will be achieved to devise an optimal augmented DPOAE test and to evaluate its utility in detecting NIHL. The first aim under simulated NIHL conditions using a 4th tone tests the hypothesis that an optimal IT level for various primary-tone level combinations can be identified that most effectively removes (suppresses) the contaminating basal source, without affecting the f2 DPOAE source. The second specific aim tests the ability of the optimized 'augmented' (f2 source) and residual DP-gram (basal source) resulting from the experiments of Specific Aim #1 to identify the extent of cochlear damage under both temporary and permanent NIHL conditions in rabbits. The hypothesis tested here is that the augmented DP- gram will reveal in rabbits with noise-induced permanent threshold shifts a larger cochlear lesion than predicted by standard DP-grams. Finally, the third specific aim will test the ability of augmented DP-grams elicited by higher-level primary tones to uncover noise-damaged cochlear regions in veterans with NIHL. The notion examined here is that high-level primary tones will be more useful under conditions of preexisting hearing loss than conventional low-level primaries using the optimized augmented DP-gram by removing basal sources that come into play to obscure damaged cochlear regions as primary-tone levels are increased. Together, the combined experiments will provide a more complete understanding of the generation of DPOAEs, which will permit the creation of a useful clinical test for diagnosing and monitoring the development of NIHL.

描述（由申请人提供）： 拟议的更新应用的总体目标是确定失真产物耳声发射（DPOAE）的特征，该特征最终将改善临床方法的早期检测到噪声引起的听力损失（NIHL），这是尤其是军事退伍军人遭受的重大感觉残疾。为此，在标准化的噪声暴露事件之前和之后，将在兔子中获得两个特殊用途的DPOAE措施，并称我们称为增强和残留的DP-Grams以及相关的DPOAE水平/相位（L/P）地图。这些dp-gram将测试以下观点：当通过使用干扰音（IT）和矢量吸收方法隔离F2-和基底源生成的DPOAE时，DPOAE响应空间中的细微后噪声变化可以更敏感地识别，而不是通过通用标准的DP-gra。在先前的研究中，我们意外（见初步研究）发现，兔子和可能的其他常见实验室物种并没有像人类那样由DPOAE频率位（FDP）引起的“反射排放”。然而，莫名其妙地表现出垂直相分带，这是反射排放的主要特征。使用抑制方法获得DPOAE L/P地图，有或没有将其放置在L/P空间内的各个频率位置，建立了DPOAES的基础耳蜗来源。该基础源被揭示为残留的DPOAE，作为“ with-it”和“没有它” dpoae l/p地图之间的矢量差。在使用IT中获得的“增强”图或DP-克术语是为了描述这些频率函数，在这种情况下，在这种情况下，将“填充”或“掩盖”的基础源删除了损害模式的真实程度。发现污染物的基础来源有望修改听力场的当前知识，即通过耳蜗发电的基本过程，并且也可能导致开发DPOAE测试，从而更敏感地识别NIHL的发作阶段。此类测试也可能在退伍军人中很有用，这些退伍军人是诊所患者，通常具有明显的听力损失，因为可以使用高级原发性音调来增加信噪比（SNR），同时保持测试的敏感性和频率特异性。将实现三个特定的目标，以设计最佳的增强DPOAE检验并评估其在检测NIHL方面的效用。使用第四音调测试模拟的NIHL条件下的第一个目标是假设，即可以鉴定出最佳的主音级组合的最佳IT水平可以鉴定出最有效地去除（抑制）污染的基础源，而不会影响F2 DPOAE源。第二个特定目标测试了优化的“增强”（F2源）和残留DP-Gram（基础源）的能力，这是由于特定目标＃1的实验而产生的，以确定兔子在临时和永久性NIHL条件下的耳蜗损害程度。这里检验的假设是，增强的DP-Gram将在兔子诱发的永久性阈值移动中揭示，比标准DP-gram所预测的更大的耳蜗病变。最后，第三个特定目标将测试由高级主音调引起的增强dp-gram的能力，以发现具有NIHL退伍军人的噪声损害的耳蜗区域。这里研究的概念是，在先前存在听力损失的条件下，使用优化的低水平原始人使用优化的增强DP-Gram，通过消除基础来源来发挥作用，以掩盖损害受损的人工耳管区域，因为主要音调增加了。共同的实验将提供对DPOAE产生的更完整了解，这将允许创建有用的临床测试，以诊断和监测NIHL的发展。