Lewis Dawna E, Valente Daniel L, Spalding Jody L
Listening and Learning Laboratory, Boys Town National Research Hospital, Omaha, Nebraska, USA.
Ear Hear. 2015 Jan;36(1):136-44. doi: 10.1097/AUD.0000000000000092.
While classroom acoustics can affect educational performance for all students, the impact for children with minimal/mild hearing loss (MMHL) may be greater than for children with normal hearing (NH). The purpose of this study was to examine the effect of MMHL on children's speech recognition comprehension and looking behavior in a simulated classroom environment. It was hypothesized that children with MMHL would perform similarly to their peers with NH on the speech recognition task but would perform more poorly on the comprehension task. Children with MMHL also were expected to look toward talkers more often than children with NH.
Eighteen children with MMHL and 18 age-matched children with NH participated. In a simulated classroom environment, children listened to lines from an elementary-age-appropriate play read by a teacher and four students reproduced over LCD monitors and loudspeakers located around the listener. A gyroscopic headtracking device was used to monitor looking behavior during the task. At the end of the play, comprehension was assessed by asking a series of 18 factual questions. Children also were asked to repeat 50 meaningful sentences with three key words each presented audio-only by a single talker either from the loudspeaker at 0 degree azimuth or randomly from the five loudspeakers.
Both children with NH and those with MMHL performed at or near ceiling on the sentence recognition task. For the comprehension task, children with MMHL performed more poorly than those with NH. Assessment of looking behavior indicated that both groups of children looked at talkers while they were speaking less than 50% of the time. In addition, the pattern of overall looking behaviors suggested that, compared with older children with NH, a larger portion of older children with MMHL may demonstrate looking behaviors similar to younger children with or without MMHL.
The results of this study demonstrate that, under realistic acoustic conditions, it is difficult to differentiate performance among children with MMHL and children with NH using a sentence recognition task. The more cognitively demanding comprehension task identified performance differences between these two groups. The comprehension task represented a condition in which the persons talking change rapidly and are not readily visible to the listener. Examination of looking behavior suggested that, in this complex task, attempting to visualize the talker may inefficiently utilize cognitive resources that would otherwise be allocated for comprehension.
虽然课堂声学环境会影响所有学生的学业表现,但对轻度/中度听力损失(MMHL)儿童的影响可能比对听力正常(NH)儿童的影响更大。本研究的目的是在模拟课堂环境中,考察MMHL对儿童言语识别理解和注视行为的影响。研究假设为,MMHL儿童在言语识别任务中的表现与NH儿童相似,但在理解任务中的表现会更差。此外,预计MMHL儿童比NH儿童更频繁地看向说话者。
18名MMHL儿童和18名年龄匹配的NH儿童参与了研究。在模拟课堂环境中,儿童听由一名教师和四名学生朗读的适合小学年龄段的戏剧台词,这些台词通过液晶显示器和位于听众周围的扬声器播放。使用陀螺头部跟踪设备在任务过程中监测注视行为。戏剧结束时,通过询问一系列18个事实性问题来评估理解情况。还要求儿童重复50个有意义的句子,每个句子包含三个关键词,由单个说话者仅通过扬声器以0度方位角播放,或从五个扬声器中随机播放。
NH儿童和MMHL儿童在句子识别任务中的表现均达到或接近上限。在理解任务中,MMHL儿童的表现比NH儿童更差。对注视行为的评估表明,两组儿童在说话者说话时看向他们的时间均不到50%。此外,总体注视行为模式表明,与年龄较大的NH儿童相比,年龄较大的MMHL儿童中,有更大比例的儿童可能表现出与年龄较小的NH或MMHL儿童相似的注视行为。
本研究结果表明,在现实的声学条件下,使用句子识别任务很难区分MMHL儿童和NH儿童的表现。认知要求更高的理解任务则能识别出这两组儿童之间的表现差异。理解任务代表了一种说话者快速变化且听众不易看到说话者的情况。对注视行为的考察表明,在这个复杂任务中,试图想象说话者可能会低效地利用原本可用于理解的认知资源。