PDF(Pubmed)
Abstract：
Older adults with hearing loss may experience difficulty recognizing speech in noise due to factors related to attenuation (e.g., reduced audibility and sensation levels, SLs) and distortion (e.g., reduced temporal fine structure, TFS, processing). Furthermore, speech recognition may improve when the amplitude modulation spectrum of the speech and masker are non-overlapping. The current study investigated this by filtering the amplitude modulation spectrum into different modulation rates for speech and speech-modulated noise. The modulation depth of the noise was manipulated to vary the SL of speech glimpses. Younger adults with normal hearing and older adults with normal or impaired hearing listened to natural speech or speech vocoded to degrade TFS cues. Control groups of younger adults were tested on all conditions with spectrally shaped speech and threshold matching noise, which reduced audibility to match that of the older hearing-impaired group. All groups benefitted from increased masker modulation depth and preservation of syllabic-rate speech modulations. Older adults with hearing loss had reduced speech recognition across all conditions. This was explained by factors related to attenuation, due to reduced SLs, and distortion, due to reduced TFS processing, which resulted in poorer auditory processing of speech cues during the dips of the masker.
摘要：
由于与衰减有关的因素，患有听力损失的老年人可能难以识别噪声中的语音（例如，降低的听觉和感觉水平，SL)和失真(例如，减少时间精细结构，TFS,处理)。此外，当语音和掩蔽器的幅度调制频谱不重叠时,语音识别可以改进。当前的研究通过将幅度调制频谱过滤为语音和语音调制噪声的不同调制速率来对此进行研究。操纵噪声的调制深度以改变语音瞥见的SL。听力正常的年轻人和听力正常或受损的老年人听自然语音或语音编码以降低TFS提示。对照组的年轻人在所有条件下进行了测试，包括频谱形状的语音和阈值匹配噪声，这降低了可听度，以匹配年龄较大的听力受损组。所有组都受益于增加的掩蔽调制深度和音节率语音调制的保留。患有听力损失的老年人在所有情况下都会降低语音识别能力。这可以通过与衰减有关的因素来解释，由于SL减少，和失真，由于减少了TFS处理，这导致掩蔽器浸入时语音提示的听觉处理较差。
