Johnstone Patti M, Litovsky Ruth Y
Waisman Center University of Wisconsin-Madison, Binaural Hearing & Speech Laboratory, 1500 Highland Avenue, Room 523, Madison, Wisconsin 53706, USA.
J Acoust Soc Am. 2006 Oct;120(4):2177-89. doi: 10.1121/1.2225416.
Speech recognition in noisy environments improves when the speech signal is spatially separated from the interfering sound. This effect, known as spatial release from masking (SRM), was recently shown in young children. The present study compared SRM in children of ages 5-7 with adults for interferers introducing energetic, informational, and/or linguistic components. Three types of interferers were used: speech, reversed speech, and modulated white noise. Two female voices with different long-term spectra were also used. Speech reception thresholds (SRTs) were compared for: Quiet (target 0 degrees front, no interferer), Front (target and interferer both 0 degrees front), and Right (interferer 90 degrees right, target 0 degrees front). Children had higher SRTs and greater masking than adults. When spatial cues were not available, adults, but not children, were able to use differences in interferer type to separate the target from the interferer. Both children and adults showed SRM. Children, unlike adults, demonstrated large amounts of SRM for a time-reversed speech interferer. In conclusion, masking and SRM vary with the type of interfering sound, and this variation interacts with age; SRM may not depend on the spectral peculiarities of a particular type of voice when the target speech and interfering speech are different sex talkers.
当语音信号与干扰声音在空间上分离时,嘈杂环境中的语音识别能力会得到提高。这种效应被称为空间掩蔽释放(SRM),最近在幼儿中得到了证实。本研究比较了5至7岁儿童与成年人在面对引入能量、信息和/或语言成分的干扰源时的SRM情况。使用了三种类型的干扰源:语音、倒序语音和调制白噪声。还使用了两个具有不同长期频谱的女性声音。比较了以下三种情况下的语音接收阈值(SRT):安静环境(目标位于正前方0度,无干扰源)、正前方环境(目标和干扰源均位于正前方0度)和右侧环境(干扰源位于右侧90度,目标位于正前方0度)。儿童的SRT高于成年人,且掩蔽效应更强。当没有空间线索时,成年人能够利用干扰源类型的差异将目标与干扰源区分开来,而儿童则不能。儿童和成年人都表现出了SRM。与成年人不同,儿童在面对倒序语音干扰源时表现出大量的SRM。总之,掩蔽和SRM会因干扰声音的类型而有所不同,并且这种差异与年龄相互作用;当目标语音和干扰语音是不同性别的说话者时,SRM可能不依赖于特定类型声音的频谱特性。