在 3 间不同混响时间的小学教室内通过汉语语言清晰度评价，研究小学课堂教 学中使用扩声系统与不使用扩声系统时不同年龄的儿童在教室内的汉语语言清晰度得 分． 结果表明:不管是 3 年级儿童还是 5 年级儿童，室内干扰噪声级较高(60dBA)时，与使 用扩声系统使听音位置声压级达到 75dBA 时的汉语语言清晰度得分相比，不使用扩声系 统和使用扩声系统但听音位置的声压级为 70 dBA 时的汉语语言清晰度得分得到明显改 善;但与在较低的教室环境噪声条件下、教师采用正常语言声压级授课时的汉语语言清晰 度得分无显著差异． 为了得到与不使用扩声系统时相同的汉语语言清晰度得分，教室内使 用扩声系统时所需信噪比应比不使用扩声系统时高 .

Chinese speech intelligibility was evaluated in 3 primary school classrooms with different reverberation time under the conditions with or without sound reinforcement system for children of different ages.The results show that，for both Grade 3 and Grade 5 children,when the interfered noise level in classrooms is relatively high (60dBA),not only the Chinese speech intelligibility scores without the sound reinforcement system but also the scores with the sound reinforcement system at a sound pressure level of 70 dBA are significantly improved and are higher than the scores with the sound reinforcement system at a sound pressure level of 75dBA.However,these in- telligibility scores are not significantly different from those obtained under the condition that the teacher uses normal speech sound pressure level to teach in quieter environmental noise conditions.It is thus concluded that,in order to obtain a speech intelligibility score equaling that without sound reinforcement system,a higher signal-to-noise ratio is needed when the sound reinforcement system is used.