Department of Hearing and Speech Sciences, University of Maryland, College Park, MD, USA.
Department of Hearing and Speech Sciences, University of Maryland, College Park, MD, USA; Walter Reed National Military Medical Center, Bethesda, MD, USA.
Clin Neurophysiol. 2018 Jun;129(6):1254-1267. doi: 10.1016/j.clinph.2018.03.024. Epub 2018 Apr 7.
Individuals with age-related hearing loss (ARHL) can restore some loss of the auditory function with the use of hearing aids (HAs). However, what remains unknown are the physiological mechanisms that underlie how the brain changes with exposure to amplified sounds though the use of HAs. We aimed to examine behavioral and physiological changes induced by HAs.
Thirty-five older-adults with moderate ARHL with no history of hearing aid use were fit with HAs tested in aided and unaided conditions, and divided into experimental and control groups. The experimental group used HAs during a period of six months. The control group did not use HAs during this period, but were given the opportunity to use them after the completion of the study. Both groups underwent testing protocols six months apart. Outcome measures included behavioral (speech-in-noise measures, self-assessment questionnaires) and electrophysiological brainstem recordings (frequency-following responses) to the speech syllable /ga/ in two quiet conditions and in six-talker babble noise.
The experimental group reported subjective benefits on self-assessment questionnaires. Significant physiological changes were observed in the experimental group, specifically a reduction in fundamental frequency magnitude, while no change was observed in controls, yielding a significant time × group interaction. Furthermore, peak latencies remained stable in the experimental group but were significantly delayed in the control group after six months. Significant correlations between behavioral and physiological changes were also observed.
The findings suggest that HAs may alter subcortical processing and offset neural timing delay; however, further investigation is needed to understand cortical changes and HA effects on cognitive processing.
The findings of the current study provide evidence for clinicians that the use of HAs may prevent further loss of auditory function resulting from sensory deprivation.
与年龄相关的听力损失(ARHL)患者可以通过使用助听器(HA)来恢复部分听觉功能。然而,目前尚不清楚的是,大脑在通过使用 HA 暴露于放大的声音时是如何发生变化的,其生理机制是什么。我们旨在研究 HA 引起的行为和生理变化。
35 名年龄较大的、有中度 ARHL 但无助听器使用史的成年人被适配 HA 并在助听和未助听条件下进行测试,并分为实验组和对照组。实验组在六个月的时间内使用 HA。对照组在此期间不使用 HA,但在研究完成后有机会使用。两组均在六个月后接受测试方案。结果测量包括行为(噪声下言语测试、自我评估问卷)和电生理脑干记录(言语音节/ga/的频率跟随反应),在两个安静条件和六个人说话的噪声中。
实验组在自我评估问卷中报告了主观受益。实验组观察到显著的生理变化,具体表现为基频幅度减小,而对照组没有变化,产生了显著的时间×组交互作用。此外,实验组的峰值潜伏期保持稳定,但对照组在六个月后显著延迟。还观察到行为和生理变化之间存在显著相关性。
研究结果表明,HA 可能改变皮质下处理并抵消神经时间延迟;然而,需要进一步研究来了解皮质变化以及 HA 对认知处理的影响。
本研究的结果为临床医生提供了证据,即使用 HA 可能防止因感觉剥夺而导致的听觉功能进一步丧失。