Assessment of hearing threshold in adults with hearing loss using an automated system of cortical auditory evoked potential detection

Abstract Introduction: The use of hearing aids by individuals with hearing loss brings a better quality of life. Access to and benefit from these devices may be compromised in patients who present difficulties or limitations in traditional behavioral audiological evaluation, such as newborns and small children, individuals with auditory neuropathy spectrum, autism, and intellectual deficits, and in adults and the elderly with dementia. These populations (or individuals) are unable to undergo a behavioral assessment, and generate a growing demand for objective methods to assess hearing. Cortical auditory evoked potentials have been used for decades to estimate hearing thresholds. Current technological advances have lead to the development of equipment that allows their clinical use, with features that enable greater accuracy, sensitivity, and specificity, and the possibility of automated detection, analysis, and recording of cortical responses. Objective: To determine and correlate behavioral auditory thresholds with cortical auditory thresholds obtained from an automated response analysis technique. Methods: The study included 52 adults, divided into two groups: 21 adults with moderate to severe hearing loss (study group); and 31 adults with normal hearing (control group). An automated system of detection, analysis, and recording of cortical responses (HEARLab®) was used to record the behavioral and cortical thresholds. The subjects remained awake in an acoustically treated environment. Altogether, 150 tone bursts at 500, 1000, 2000, and 4000 Hz were presented through insert earphones in descending-ascending intensity. The lowest level at which the subject detected the sound stimulus was defined as the behavioral (hearing) threshold (BT). The lowest level at which a cortical response was observed was defined as the cortical electrophysiological threshold. These two responses were correlated using linear regression. Results: The cortical electrophysiological threshold was, on average, 7.8 dB higher than the behavioral for the group with hearing loss and, on average, 14.5 dB higher for the group without hearing loss for all studied frequencies. Conclusion: The cortical electrophysiological thresholds obtained with the use of an automated response detection system were highly correlated with behavioral thresholds in the group of individuals with hearing loss.

摘要：听力损失患者使用助听器可提升其生活质量，但新生儿、幼儿、听神经病谱系（auditory neuropathy spectrum）人群、孤独症患者、智力障碍者，以及罹患痴呆的成年人与老年人等群体，难以开展传统行为听力学评估，因此获取并使用助听器获益的可能性会受到限制。此类人群无法完成行为听力学评估，进而对听力评估的客观方法产生了日益增长的需求。皮层听觉诱发电位（cortical auditory evoked potentials）已被用于估算听阈数十年。当前的技术进步推动了可用于临床的相关设备研发，此类设备具备更高的准确性、灵敏度与特异性，同时可实现皮层响应的自动检测、分析与记录。
研究目的：明确行为听阈与通过自动响应分析技术获取的皮层听觉听阈，并对二者开展相关性分析。
方法：本研究纳入52名成年人，分为两组：研究组21名，为中度至重度听力损失患者；对照组31名，为听力正常者。采用皮层响应自动检测、分析与记录系统（HEARLab®）采集行为听阈与皮层听阈。受试者在隔音环境中保持清醒状态。通过插入式耳机以先降后升的强度序列，给予受试者500、1000、2000及4000 Hz的短纯音刺激，共计150次。受试者可察觉声刺激的最低强度被定义为行为听阈（BT）；观测到皮层响应的最低强度被定义为皮层电生理听阈。采用线性回归方法对两种听阈进行相关性分析。
结果：在所有研究频率下，听力损失组的皮层电生理听阈平均较行为听阈高7.8 dB，听力正常组则平均高14.5 dB。
结论：采用自动响应检测系统获取的皮层电生理听阈，与听力损失组的行为听阈具有高度相关性。