Effects of masking noise on vowel and sibilant contrasts in normal-hearing speakers and postlingually deafened cochlear implant users
Effects of masking noise on vowel and sibilant contrasts in normal-hearing speakers and postlingually deafened cochlear implant users
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DOI：
10.1121/1.2384848
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发表时间：
2007-01-01
影响因子：
2.4
通讯作者：
Burton, Ellen
中科院分区：
文献类型：
--
作者：
Perkell, Joseph S.;Denny, Margaret;Burton, Ellen
通过检查在信噪比 (N/S) 增加的情况下说话者的音素对比，研究了听觉反馈在语音产生中的作用。七名人工耳蜗使用者和七名听力正常的对照者发出包含元音 /i/、/u/、/epsilon/ 和 /ae/ 以及咝音 /s/ 和 /integral/ 的话语，同时听到他们的讲话与噪声混合在一起，在他们的检测阈值和不适阈值之间有七个等间隔的级别。说话者的平均元音持续时间和声压级通常随着 N/S 的增加而增加。平均元音对比度最初持平或上升；在较高的 N/S 水平下，它会下降。对比度的增加被解释为反映了扬声器在降低的声学传输条件下保持清晰度的尝试。随着 N/S 的增加，说话者可以更有效地检测其音素对比的程度，并且省力的竞争影响导致对比减弱。嘶嘶声对比更容易受到噪音的影响；对于对照来说，它在 N/S 增加的整个范围内下降，并且对于种植体用户来说是可变的。结果被解释为反映了清晰度限制、工作经济性和掩蔽对实现听觉音素目标的影响的综合影响——与对照组相比，植入物用户增加噪声对比度的能力较差。 (c) 2007 年美国声学学会。
The role of auditory feedback in speech production was investigated by examining speakers' phonemic contrasts produced under increases in the noise to signal ratio (N/S). Seven cochlear implant users and seven normal-hearing controls pronounced utterances containing the vowels /i/, /u/, /epsilon/ and /ae/ and the sibilants /s/ and /integral/ while hearing their speech mixed with noise at seven equally spaced levels between their thresholds of detection and discomfort. Speakers' average vowel duration and SPL generally rose with increasing N/S. Average vowel contrast was initially flat or rising; at higher N/S levels, it fell. A contrast increase is interpreted as reflecting speakers' attempts to maintain clarity under degraded acoustic transmission conditions. As N/S increased, speakers could detect the extent of their phonemic contrasts less effectively, and the competing influence of economy of effort led to contrast decrements. The sibilant contrast was more vulnerable to noise; it decreased over the entire range of increasing N/S for controls and was variable for implant users. The results are interpreted as reflecting the combined influences of a clarity constraint, economy of effort and the effect of masking on achieving auditory phonemic goals-with implant users less able to increase contrasts in noise than controls. (c) 2007 Acoustical Society of America.