Hearing Research Center, Boston University, Boston, Massachusetts, USA.
Ear Hear. 2010 Apr;31(2):213-20. doi: 10.1097/AUD.0b013e3181c34ba6.
To examine the impact of hearing impairment on a listener's ability to process simultaneous spoken messages.
Nine young listeners with bilateral sensorineural hearing loss and nine young listeners with normal hearing participated in this study. Two messages of equal level were presented separately to the two ears. The messages were systematically degraded by adding speech-shaped noise. Listeners performed a single task in which report of one message was required and a dual task in which report of both messages was required.
As the level of the added noise was increased, performance on both single and dual tasks declined. In the dual task, performance on the message reported second was poorer and more sensitive to the noise level than performance on the message reported first. When compared to listeners with normal hearing, listeners with hearing loss showed a larger deficit in recall of the second message than the first. This difference disappeared when performance of the hearing loss group was compared to that of the normal-hearing group at a poorer signal to noise ratio.
A listener's ability to process a secondary message is more sensitive to noise and hearing impairment than the ability to process a primary message. Tasks involving the processing of simultaneous messages may be useful for assessing hearing handicap and the benefits of rehabilitation in realistic listening scenarios.
研究听力障碍对听众处理同时传入的言语信息能力的影响。
本研究纳入了 9 名双侧感音神经性听力损失的年轻受试者和 9 名听力正常的年轻受试者。两个等响度的信息分别传入双耳。通过添加语音噪声使信息逐渐失真。受试者完成单项任务（只需报告一个信息）和双项任务（需报告两个信息）。
随着外加噪声水平的提高，单项任务和双项任务的表现均下降。在双项任务中，报告第二个信息的成绩更差，对噪声水平更敏感，而报告第一个信息的成绩则不受影响。与听力正常的受试者相比，听力损失的受试者对第二个信息的回忆能力明显下降，而对第一个信息的回忆能力则没有明显差异。当将听力损失组与信噪比较差时的听力正常组的表现进行比较时，这种差异消失了。
与处理首要信息相比，听众处理次要信息的能力对噪声和听力障碍更为敏感。涉及同时处理多个信息的任务可能有助于评估在现实聆听场景中的听力障碍和康复效果。
