Léger Agnès C, Ives David T, Lorenzi Christian
Research Laboratory of Electronics, Massachusetts Institute of Technology, Room 36-757, 77 Massachusetts Avenue, Cambridge, MA 02139-4307, USA.
Laboratoire des systèmes perceptifs, UMR CNRS 8248, Département d'Etudes Cognitives, Institut d'Etude de la Cognition, École normale supérieure, Paris Sciences et Lettres, 29 rue d'Ulm, 75005 Paris, France.
Hear Res. 2014 Oct;316:102-9. doi: 10.1016/j.heares.2014.07.008. Epub 2014 Aug 11.
The ability to identify syllables in the presence of speech-shaped noise and a single-talker background was measured for 18 normal-hearing (NH) listeners, and for eight hearing-impaired (HI) listeners with near-normal audiometric thresholds for frequencies up to 1.5 kHz and a moderate to severe hearing loss above 2 kHz. The stimulus components were restricted to the low-frequency (≤1.5 kHz) region, where audiometric thresholds were classified clinically as normal or near normal for all listeners. Syllable identification in a speech background was measured as a function of the fundamental-frequency (F0) difference between competing voices (ranging from 1 semitone to ∼1 octave). HI listeners had poorer syllable intelligibility than NH listeners in all conditions. Intelligibility decreased by about the same amount for both groups when the F0 difference between competing voices was reduced. The results suggest that the ability to identify speech against noise or an interfering talker was disrupted in frequency regions of near-normal hearing for HI listeners, but that the ability to benefit from the tested F0 differences was not disrupted. This deficit was not predicted by the elevated absolute thresholds for speech in speech, but it was for speech in noise. It may result from supra-threshold auditory deficits associated with aging.
针对18名听力正常（NH）的听众以及8名听力受损（HI）的听众，测量了他们在语音形状噪声和单说话者背景下识别音节的能力。这8名听力受损的听众在1.5kHz以下频率的听力阈值接近正常，但在2kHz以上存在中度至重度听力损失。刺激成分被限制在低频（≤1.5kHz）区域，在该区域所有听众的听力阈值在临床上被分类为正常或接近正常。在语音背景下的音节识别作为竞争声音之间基频（F0）差异的函数进行测量（范围从1个半音到约1个八度）。在所有条件下，听力受损的听众的音节清晰度都比听力正常的听众差。当竞争声音之间的F0差异减小时，两组的清晰度下降量大致相同。结果表明，在听力接近正常的频率区域，听力受损的听众识别对抗噪声或干扰说话者的语音的能力受到了干扰，但从测试的F0差异中获益的能力没有受到干扰。这种缺陷不是由语音中语音的绝对阈值升高所预测的，但对于噪声中的语音是可以预测的。它可能是由与衰老相关的阈上听觉缺陷导致的。
