Department of Otolaryngology, New York University School of Medicine, New York, New York 10016, USA.
Ear Hear. 2010 Jun;31(3):336-44. doi: 10.1097/AUD.0b013e3181d3d514.
The purpose of this study is to determine how combinations of noise levels and reverberation typical of ranges found in current classrooms will affect speech recognition performance of typically developing children with normal speech, language, and hearing and to compare their performance with that of adults with normal hearing. Speech recognition performance was measured using the Bamford-Kowal-Bench Speech in Noise test. A virtual test paradigm represented the signal reaching a student seated in the back of a classroom with a volume of 228 m and with varied reverberation time (0.3, 0.6, and 0.8 sec). The signal to noise ratios required for 50% performance (SNR-50) and for 95% performance were determined for groups of children aged 6 to 12 yrs and a group of young adults with normal hearing.
This is a cross-sectional developmental study incorporating a repeated measures design. Experimental variables included age and reverberation time. A total of 63 children with normal hearing and typically developing speech and language and nine adults with normal hearing were tested. Nine children were included in each age group (6, 7, 8, 9, 10, 11, and 12 yrs).
The SNR-50 increased significantly with increased reverberation and decreased significantly with increasing age. On average, children required positive SNRs for 50% performance, whereas thresholds for adults were close to 0 dB or <0 dB for the conditions tested. When reverberant SNR-50 was compared with adult SNR-50 without reverberation, adults did not exhibit an SNR loss, but children aged 6 to 8 yrs exhibited a moderate SNR loss and children aged 9 to 12 yrs exhibited a mild SNR loss. To obtain average speech recognition scores of 95% at the back of the classroom, an SNR > or = 10 dB is required for all children at the lowest reverberation time, of > or = 12 dB for children up to age 11 yrs at the 0.6-sec reverberant condition, and of > or = 15 dB for children aged 7 to 11 yrs at the 0.8-sec condition. The youngest children require even higher SNRs in the 0.8-sec condition.
Results highlight changes in speech recognition performance with age in elementary school children listening to speech in noisy, reverberant classrooms. The more reverberant the environment, the better the SNR required. The younger the child, the better the SNR required. Results support the importance of attention to classroom acoustics and emphasize the need for maximizing SNR in classrooms, especially in classrooms designed for early childhood grades.
本研究旨在确定在当前教室中常见的噪声水平和混响组合如何影响具有正常言语、语言和听力的典型发育儿童的言语识别性能，并将其与正常听力的成人进行比较。言语识别性能使用 Bamford-Kowal-Bench 语音噪声测试进行测量。虚拟测试范例代表了信号到达教室后排学生的情况，音量为 228 米，混响时间不同（0.3、0.6 和 0.8 秒）。为 6 至 12 岁的儿童组和一组正常听力的年轻成人确定了 50%性能（SNR-50）和 95%性能所需的信噪比。
这是一项包含重复测量设计的跨期发育研究。实验变量包括年龄和混响时间。共测试了 63 名具有正常听力和正常言语及语言发育的儿童和 9 名正常听力的成年人。每个年龄组（6、7、8、9、10、11 和 12 岁）均包括 9 名儿童。
SNR-50 随混响增加而显著增加，随年龄增加而显著降低。平均而言，儿童需要正 SNR 才能达到 50%的性能，而成年人的阈值在测试条件下接近 0dB 或<0dB。当比较混响 SNR-50 与无混响的成人 SNR-50 时，成年人没有表现出 SNR 损失，但 6 至 8 岁的儿童表现出中度 SNR 损失，9 至 12 岁的儿童表现出轻度 SNR 损失。为了在教室后排获得平均 95%的言语识别分数，在最低混响时间下，所有儿童都需要>或=10dB 的 SNR，在 0.6 秒混响条件下，11 岁以下儿童需要>或=12dB 的 SNR，在 0.8 秒条件下，7 至 11 岁儿童需要>或=15dB 的 SNR。年幼的孩子在 0.8 秒的条件下甚至需要更高的 SNR。
结果突出了小学生在嘈杂、混响的教室中聆听言语时年龄对言语识别性能的影响。环境的混响越严重，所需的 SNR 就越好。孩子越小，所需的 SNR 就越好。结果支持对教室声学的重视，并强调需要在教室中最大限度地提高 SNR，尤其是在为幼儿年级设计的教室中。
