Intelligibility of dysphonic speech in classrooms (Botallico et al., 2023)

Purpose: The purpose of this project is to assess the acoustical conditions in which optimal intelligibility and low listening difficulty can be achieved in real classrooms for elementary students, taking into consideration the effects of dysphonic voice and typical classroom noise.Method: Speech intelligibility tests were performed in six elementary classrooms with 80 normal-hearing students aged 7–11 years. The speech material was produced by a female actor using a normal voice quality and simulating a dysphonic voice. The stimuli were played by a Head and Torso Simulator. Child babble noise and classrooms with different reverberation times were used to obtain a Speech Transmission Index (STI) range from 0.2 to 0.7, corresponding to the categories bad, poor, fair, and good.Results: The results showed a statistically significant decrease in intelligibility when the speaker was dysphonic, in STI higher than 0.33. The rating of listening difficulty showed a significantly greater difficulty in perceiving the dysphonic voice. In addition, younger children showed poorer performance and greater listening difficulty compared with older children when listening to the normal voice quality. Both groups were equally impacted when the voice was dysphonic.Conclusions: The results suggested that better acoustic conditions are needed for children to reach a good level of intelligibility and to reduce listening difficulty if the teacher is suffering from voice problems. This was true for children regardless of grade level, highlighting the importance of ensuring more favorable acoustic conditions for children throughout all elementary schools.Supplemental Material S1. Acoustic parameters recorded in the six classrooms from each microphone and each noise condition.Supplemental Material S2. Mean values, standard deviation, standard error and confidence interval for intelligibility score and listening difficulty for each conditions.Bottalico, P., Murgia, S., Mekus, T., & Flaherty, M. (2023). Classroom acoustics for enhancing students’ understanding when a teacher suffers from a dysphonic voice. Language, Speech, and Hearing Services in Schools, 54(4), 1195–1207. https://doi.org/10.1044/2023_LSHSS-22-00158

项目宗旨：本项目的宗旨在于评估在真实教室环境中，针对小学生实现最佳可懂度和低听辨难度的声学条件，同时考虑声哑嗓音及典型教室噪音的影响。研究方法：在六所小学的教室中，对80名7至11岁的正常听力学生进行了语音可懂度测试。语音材料由一名女性演员以正常嗓音质量和模拟声哑嗓音的方式录制。刺激信号由头部和躯干模拟器播放。使用儿童咿呀声和不同混响时间的教室，以获得从0.2到0.7的语音传输指数（STI）范围，对应于“差”、“较差”、“一般”和“良好”的分类。研究结果：结果显示，当说话者声哑且STI高于0.33时，可懂度显著下降。听辨难度的评分显示出识别声哑嗓音的显著难度。此外，与年长儿童相比，年幼儿童在听正常嗓音质量时表现较差，听辨难度更大。当嗓音为声哑时，两组均受到同等影响。研究结论：结果表明，若教师患有声哑，则需要更好的声学条件以帮助儿童达到良好的可懂度并降低听辨难度。这一结论对各个年级的学生均适用，凸显了确保小学各校均有更佳声学条件的重要性。补充材料S1：记录自六间教室中每个麦克风的每个噪音条件下的声学参数。补充材料S2：每个条件下可懂度评分和听辨难度的平均值、标准差、标准误和置信区间。Bottalico, P., Murgia, S., Mekus, T., & Flaherty, M. (2023). 患声哑嗓音教师授课时提升学生理解力的教室声学。语言、语音与听觉学校服务，54(4)，1195–1207. https://doi.org/10.1044/2023_LSHSS-22-00158