Center for Hearing Research, Boys Town National Research Hospital, Omaha, Nebraska, USA.
Ear Hear. 2020 Jul/Aug;41(4):705-719. doi: 10.1097/AUD.0000000000000830.
The purpose of this study was to examine age- and hearing-related differences in school-age children's benefit from visual speech cues. The study addressed three questions: (1) Do age and hearing loss affect degree of audiovisual (AV) speech enhancement in school-age children? (2) Are there age- and hearing-related differences in the mechanisms underlying AV speech enhancement in school-age children? (3) What cognitive and linguistic variables predict individual differences in AV benefit among school-age children?
Forty-eight children between 6 and 13 years of age (19 with mild to severe sensorineural hearing loss; 29 with normal hearing) and 14 adults with normal hearing completed measures of auditory and AV syllable detection and/or sentence recognition in a two-talker masker type and a spectrally matched noise. Children also completed standardized behavioral measures of receptive vocabulary, visuospatial working memory, and executive attention. Mixed linear modeling was used to examine effects of modality, listener group, and masker on sentence recognition accuracy and syllable detection thresholds. Pearson correlations were used to examine the relationship between individual differences in children's AV enhancement (AV-auditory-only) and age, vocabulary, working memory, executive attention, and degree of hearing loss.
Significant AV enhancement was observed across all tasks, masker types, and listener groups. AV enhancement of sentence recognition was similar across maskers, but children with normal hearing exhibited less AV enhancement of sentence recognition than adults with normal hearing and children with hearing loss. AV enhancement of syllable detection was greater in the two-talker masker than the noise masker, but did not vary significantly across listener groups. Degree of hearing loss positively correlated with individual differences in AV benefit on the sentence recognition task in noise, but not on the detection task. None of the cognitive and linguistic variables correlated with individual differences in AV enhancement of syllable detection or sentence recognition.
Although AV benefit to syllable detection results from the use of visual speech to increase temporal expectancy, AV benefit to sentence recognition requires that an observer extracts phonetic information from the visual speech signal. The findings from this study suggest that all listener groups were equally good at using temporal cues in visual speech to detect auditory speech, but that adults with normal hearing and children with hearing loss were better than children with normal hearing at extracting phonetic information from the visual signal and/or using visual speech information to access phonetic/lexical representations in long-term memory. These results suggest that standard, auditory-only clinical speech recognition measures likely underestimate real-world speech recognition skills of children with mild to severe hearing loss.
本研究旨在探讨年龄和听力相关因素对学龄儿童从视觉言语线索中获益的影响。研究主要关注三个问题：（1）年龄和听力损失是否会影响学龄儿童的视听（AV）语音增强程度？（2）在学龄儿童的视听语音增强机制中是否存在年龄和听力相关的差异？（3）哪些认知和语言变量可以预测学龄儿童在 AV 获益方面的个体差异？
48 名 6 至 13 岁的儿童（19 名患有轻度至重度感音神经性听力损失；29 名听力正常）和 14 名听力正常的成年人在双说话人掩蔽类型和频谱匹配噪声中完成了听觉和 AV 音节检测和/或句子识别的测量。儿童还完成了标准化的接受性词汇、视空间工作记忆和执行注意的行为测量。混合线性模型用于检查模态、听众组和掩蔽对句子识别准确性和音节检测阈值的影响。皮尔逊相关用于检查儿童 AV 增强（AV-仅听觉）与年龄、词汇量、工作记忆、执行注意和听力损失程度之间的个体差异的关系。
在所有任务、掩蔽类型和听众组中都观察到了显著的 AV 增强。在两种掩蔽器中，句子识别的 AV 增强相似，但听力正常的儿童的句子识别的 AV 增强不如听力正常的成年人和听力损失的儿童显著。音节检测的 AV 增强在双说话人掩蔽器中大于噪声掩蔽器，但在听众组之间没有显著差异。听力损失程度与噪声中句子识别任务的 AV 获益个体差异呈正相关，但与检测任务无关。认知和语言变量均与音节检测或句子识别的 AV 增强个体差异无关。
尽管 AV 对音节检测的增强是通过使用视觉言语来增加时间预期的结果，但 AV 对句子识别的增强需要观察者从视觉言语信号中提取语音信息。本研究的结果表明，所有听众组在使用视觉言语中的时间线索来检测听觉言语方面都同样出色，但听力正常的成年人和听力损失的儿童比听力正常的儿童更善于从视觉信号中提取语音信息，或者利用视觉言语信息访问长期记忆中的语音/词汇表征。这些结果表明，标准的、仅听觉的临床言语识别测量可能低估了轻度至重度听力损失儿童的实际言语识别技能。
