The role of acoustic treatment in speech intelligibility and cognitive performance in university classrooms

This study aimed to enhance classroom acoustics through the use of sound-absorbing panels and to examine their effects on speech intelligibility and cognitive performance. Two classrooms were selected to measure acoustic parameters, including reverberation time, equivalent sound pressure level, and speech transmission index. Students’ sustained attention and working memory were assessed using the SART and 2-BACK cognitive tests. Sound-absorbing panels were then manufactured and installed in one of the classrooms to evaluate their impact on speech intelligibility and cognitive performance. The results showed that in the intervention classroom, the reverberation time was reduced from 1.17 s to 0.74 s, and the equivalent sound pressure level decreased by 2 dB. Consequently, the speech transmission index improved by 10%. While the sound-absorbing panels did not significantly reduce the average percentage of errors and reaction times during the sustained attention test, improving the classroom’s acoustic conditions resulted in better performance on the working memory test.