Hall Joseph W, Buss Emily, Grose John H
Department of Otolaryngology-Head and Neck Surgery, University of North Carolina at Chapel Hill, 170 Manning Drive, Chapel Hill, North Carolina 27599-7070.
J Acoust Soc Am. 2014 Jun;135(6):3594-600. doi: 10.1121/1.4873518.
This study investigated development of the ability to integrate glimpses of speech in modulated noise. Noise was modulated synchronously across frequency or asynchronously such that when noise below 1300 Hz was "off," noise above 1300 Hz was "on," and vice versa. Asynchronous masking was used to examine the ability of listeners to integrate speech glimpses separated across time and frequency. The study used the Word Intelligibility by Picture Identification (WIPI) test and included adults, older children (age 8-10 yr) and younger children (5-7 yr). Results showed poorer masking release for the children than the adults for synchronous modulation but not for asynchronous modulation. It is possible that children can integrate cues relatively well when all intervals provide at least partial speech information (asynchronous modulation) but less well when some intervals provide little or no information (synchronous modulation). Control conditions indicated that children appeared to derive less benefit than adults from speech cues below 1300 Hz. This frequency effect was supported by supplementary conditions where the noise was unmodulated and the speech was low- or high-pass filtered. Possible sources of the developmental frequency effect include differences in frequency weighting, effective speech bandwidth, and the signal-to-noise ratio in the unmodulated noise condition.
本研究调查了在调制噪声中整合语音片段的能力发展情况。噪声在频率上进行同步调制或异步调制，使得当1300赫兹以下的噪声“关闭”时，1300赫兹以上的噪声“打开”，反之亦然。异步掩蔽用于检验听众整合在时间和频率上分离的语音片段的能力。该研究使用了图片识别单词可懂度（WIPI）测试，涵盖了成年人、大龄儿童（8至10岁）和小龄儿童（5至7岁）。结果显示，对于同步调制，儿童的掩蔽释放比成年人差，但对于异步调制则不然。当所有间隔都至少提供部分语音信息时（异步调制），儿童可能相对较好地整合线索，但当某些间隔提供很少或没有信息时（同步调制），整合效果则较差。对照条件表明，儿童从1300赫兹以下的语音线索中获得的益处似乎比成年人少。在噪声未调制且语音进行低通或高通滤波的补充条件下，这种频率效应得到了支持。发育性频率效应的可能来源包括频率加权、有效语音带宽以及未调制噪声条件下的信噪比差异。
