Investigation of low-sound-level auditory processing deficits after chronic exposure to very high noise levels.

听力损失通常被定义为对安静声音的敏感性丧失。然而，它反映了由于遗传等因素或生活方式（如饮食，吸烟，运动和暴露于噪音）造成的损害的积累。因此，对听力系统的损害可能存在于多个部位，精确的模式几乎是唯一的，就像“指纹”一样。除了灵敏度的丧失，最近的研究表明，暴露在非常高的声级下会导致检测声音中低幅度波动的能力降低。声音的波动对于交流信息很重要，例如在演讲中，或音乐中的旋律。这项工作的目的是衡量这一新发现的赤字的影响，听力损失的人，一个人口的疾病很可能是更进一步的进展比在年轻的人口研究到目前为止。重要性虽然噪音在工作中的规定，减少了噪音暴露在工作场所，暴露在高声级“娱乐”设置显着增加。在英国，这种对噪声暴露的贡献的流行率估计在1980年至1994年之间增加了两倍（Smith等人，2000年）。只有在夜总会和摇滚音乐会的常客中才表现出对波动的处理不足。这种新的缺陷在21岁的男性中是可测量的，但只在他们听力的相对较小的范围内，因此可能只产生一个小的障碍。到29岁时，这种缺陷更加明显，并与传统的敏感性丧失并存。即使在老年人中，临床测量也将这种损失归类为“正常”范围内，不太可能从助听器中受益。除此之外，一种“隐性”听力损失正在发展。随着人口老龄化，娱乐活动的增加意味着未来听力损失的增加。这种缺陷可能意味着受试者从助听器中获得的益处比预期的要少。需要提供这种隐藏损失的更好诊断，目的是生产适合患者独特听力损失的助听器配件。方法使用听力受损的主题与高水平的噪音暴露的历史，我们将测量有多少新报告的赤字已经蔓延相比，在以前的测试，年轻，人口。这个过程需要使用专业测试信号，要求受试者对这些信号做出反应。我们还致力于共同开发不需要受试者有意识输入的技术，通过测量大脑对声音的反应来实现。然后，我们将这些测量与佩戴助听器时在噪声中说话测试中的表现相关联。我们将比较这一组的结果与一组听力损伤不是由噪音暴露引起的。最后，我们将评估改变助听器中信号处理的速度是否与测得的缺陷相互作用，从而改善佩戴者的结果。好处更好地定义对听力损失的贡献将导致产生更现实的期望，并传达给患者。根据特定的损失调整助听器应该会带来更大的帮助效果，从而带来感知的好处，并且希望更大的坚持。除了改善补救措施外，这项工作还应确定一种适当的测试方法，可以发现高危人群中缺陷的早期阶段，以便进行行为矫正。

AimsHearing loss is usually defined as a loss of sensitivity to quiet sounds. However, it reflects the accumulation of damage due to factors such as genetics, or lifestyle such as diet, smoking, exercise and exposure to noise. Consequently, damage to the hearing system is likely to be present in multiple sites, the precise pattern being almost unique, like a "fingerprint". Besides the loss of sensitivity, recent work has shown that exposure to very high sound levels can lead to reduced ability to detect low-amplitude fluctuations in sounds. Fluctuations in sounds are important for communicating information, such as in speech, or melody in music. The aim of this work is to measure the impact of this newly identified deficit in people with hearing loss, a population where the disease is likely to be much further progressed than in the younger populations studied to date.Importance Although noise-at-work regulations have reduced noise exposure in the workplace, exposure to high sound levels "recreational" settings has increased markedly. In the UK, the prevalence of this contribution to noise exposure was estimated to have tripled between 1980 and 1994 (Smith et al., 2000). Deficient processing of fluctuations was only demonstrated in regular attendees at nightclubs and rock concerts. The new deficit was measurable in 21-year old males, but only in a comparatively small range of their hearing, so may only produce a small handicap. By age 29, the deficit is more obvious, and co-exists alongside the traditional loss of sensitivity. Even in this older population, clinical measures classify this loss as within "normal" bounds, and unlikely to benefit from hearing aids. Underneath this, a "hidden" hearing loss is developing.Increased recreational exposure, alongside an ageing population, implies future increases in this deficit. This deficit could mean that subjects will receive less benefit than expected from a hearing aid. There is a need to provide better diagnosis of this hidden loss with the intention of producing hearing aid fittings tailored to the patient's unique hearing loss. MethodsUsing hearing-impaired subjects with a history of high-level noise exposure, we will measure how much the newly reported deficit has spread compared to that seen in the previously tested, younger, populations. This process requires the use of specialist test signals to which the subject is asked to respond. We also aim to co-develop techniques that require no conscious input from the subject, by use of measuring brain activity in response to sounds.We then will correlate these measures against performance on speech-in-noise tests when wearing hearing aids. We will compare results from this group against a group whose hearing impairment does not arise from noise exposure. Finally, we will assess if varying the speed of signal processing in the hearing aid interacts with the measured deficit so as to improve outcomes for the wearer.BenefitsBetter definition of the contributions to hearing loss will lead to the generation of more realistic expectations to be communicated to the patient. Tuning the hearing aid to the particular loss should lead to greater effectiveness of aiding and hence perceived benefit, and, hopefully, greater adherence. Apart from improving remediation, the work should also identify a suitable test that can detect the early stages of the deficit in at-risk populations, so that behavioural modification can be applied.