Waisman Center, 5228University of Wisconsin-Madison, Madison, WI, USA.
Trends Hear. 2021 Jan-Dec;25:23312165211045313. doi: 10.1177/23312165211045313.
In complex listening environments, children can benefit from auditory spatial cues to understand speech in noise. When a spatial separation is introduced between the target and masker and/or listening with two ears versus one ear, children can gain intelligibility benefits with access to one or more auditory cues for unmasking: monaural head shadow, binaural redundancy, and interaural differences. This study systematically quantified the contribution of individual auditory cues in providing binaural speech intelligibility benefits for children with normal hearing between 6 and 15 years old. In virtual auditory space, target speech was presented from + 90° azimuth (i.e., listener's right), and two-talker babble maskers were either co-located (+ 90° azimuth) or separated by 180° (-90° azimuth, listener's left). Testing was conducted over headphones in monaural (i.e., right ear) or binaural (i.e., both ears) conditions. Results showed continuous improvement of speech reception threshold (SRT) between 6 and 15 years old and immature performance at 15 years of age for both SRTs and intelligibility benefits from more than one auditory cue. With early maturation of head shadow, the prolonged maturation of unmasking was likely driven by children's poorer ability to gain full benefits from interaural difference cues. In addition, children demonstrated a trade-off between the benefits from head shadow versus interaural differences, suggesting an important aspect of individual differences in accessing auditory cues for binaural intelligibility benefits during development.
在复杂的聆听环境中，儿童可以受益于听觉空间线索来理解噪声中的言语。当目标和掩蔽之间引入空间分离，或者用双耳而非单耳聆听时，儿童可以通过获得一个或多个用于去掩蔽的听觉线索来提高可懂度：单耳头部遮蔽、双耳冗余和两耳间差异。本研究系统地量化了个体听觉线索在为 6 至 15 岁正常听力儿童提供双耳言语可懂度增益方面的贡献。在虚拟听觉空间中，目标语音从 +90°方位（即听者的右侧）呈现，两个说话者的噪声掩蔽要么位于同一位置（+90°方位），要么相隔 180°（-90°方位，听者的左侧）。测试在耳机中进行，采用单耳（即右耳）或双耳（即双耳）条件。结果表明，6 至 15 岁儿童的言语接收阈值（SRT）持续改善，而 15 岁儿童的 SRT 和来自多个听觉线索的可懂度增益表现不成熟。由于头部遮蔽的早期成熟，掩蔽的不成熟可能是由于儿童从两耳间差异线索中获得充分增益的能力较差所致。此外，儿童表现出头部遮蔽与两耳间差异之间的收益权衡，这表明个体在获取双耳可懂度增益的听觉线索方面存在差异的一个重要方面。
