4.6 Article

Altered neural encoding of vowels in noise does not affect behavioral vowel discrimination in gerbils with age-related hearing loss

期刊

FRONTIERS IN NEUROSCIENCE
卷 17, 期 -, 页码 -

出版社

FRONTIERS MEDIA SA
DOI: 10.3389/fnins.2023.1238941

关键词

presbycusis; consonant-vowel-consonant logatomes; Mongolian gerbil; speech-in-noise perception; temporal coding

向作者/读者索取更多资源

Understanding speech in a noisy environment becomes more difficult with increasing age. This study on gerbils found that while the perception of speech-in-noise deteriorates with age, behavioral vowel discrimination remains unaffected.
IntroductionUnderstanding speech in a noisy environment, as opposed to speech in quiet, becomes increasingly more difficult with increasing age. Using the quiet-aged gerbil, we studied the effects of aging on speech-in-noise processing. Specifically, behavioral vowel discrimination and the encoding of these vowels by single auditory-nerve fibers were compared, to elucidate some of the underlying mechanisms of age-related speech-in-noise perception deficits.MethodsYoung-adult and quiet-aged Mongolian gerbils, of either sex, were trained to discriminate a deviant naturally-spoken vowel in a sequence of vowel standards against a speech-like background noise. In addition, we recorded responses from single auditory-nerve fibers of young-adult and quiet-aged gerbils while presenting the same speech stimuli.ResultsBehavioral vowel discrimination was not significantly affected by aging. For both young-adult and quiet-aged gerbils, the behavioral discrimination between /eMODIFIER LETTER TRIANGULAR COLON/ and /iMODIFIER LETTER TRIANGULAR COLON/ was more difficult to make than /eMODIFIER LETTER TRIANGULAR COLON/ vs. /aMODIFIER LETTER TRIANGULAR COLON/ or /iMODIFIER LETTER TRIANGULAR COLON/ vs. /aMODIFIER LETTER TRIANGULAR COLON/, as evidenced by longer response times and lower d' values. In young-adults, spike timing-based vowel discrimination agreed with the behavioral vowel discrimination, while in quiet-aged gerbils it did not. Paradoxically, discrimination between vowels based on temporal responses was enhanced in aged gerbils for all vowel comparisons. Representation schemes, based on the spectrum of the inter-spike interval histogram, revealed stronger encoding of both the fundamental and the lower formant frequencies in fibers of quiet-aged gerbils, but no qualitative changes in vowel encoding. Elevated thresholds in combination with a fixed stimulus level, i.e., lower sensation levels of the stimuli for old individuals, can explain the enhanced temporal coding of the vowels in noise.DiscussionThese results suggest that the altered auditory-nerve discrimination metrics in old gerbils may mask age-related deterioration in the central (auditory) system to the extent that behavioral vowel discrimination matches that of the young adults.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.6
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据