Department of Communication Sciences and Disorders, Northwestern University, Evanston, IL 60208, USA.
Hear Res. 2010 Dec 1;270(1-2):151-7. doi: 10.1016/j.heares.2010.08.001. Epub 2010 Aug 12.
Children often have difficulty understanding speech in challenging listening environments. In the absence of peripheral hearing loss, these speech perception difficulties may arise from dysfunction at more central levels in the auditory system, including subcortical structures. We examined brainstem encoding of pitch in a speech syllable in 38 school-age children. In children with poor speech-in-noise perception, we find impaired encoding of the fundamental frequency and the second harmonic, two important cues for pitch perception. Pitch, an essential factor in speaker identification, aids the listener in tracking a specific voice from a background of voices. These results suggest that the robustness of subcortical neural encoding of pitch features in time-varying signals is a key factor in determining success with perceiving speech in noise.
儿童在有挑战性的听力环境中常常难以理解言语。在外周听力正常的情况下,这些言语感知困难可能源于听觉系统更中枢水平的功能障碍,包括皮质下结构。我们检查了 38 名学龄儿童在言语音节中对音高的脑干编码。在言语感知能力差的儿童中,我们发现基频和第二谐波的编码受损,这是音高感知的两个重要线索。音高是说话人识别的一个重要因素,有助于听众在背景声音中跟踪特定的声音。这些结果表明,时间变化信号中皮质下神经对音高特征的编码稳健性是决定在噪声中感知言语成功与否的关键因素。