An effective learning process in a classroom with good speech intelligibility requires good acoustic quality. Low acoustic quality may cause frequent speech repetition and consequently leads to several emotional disorders among the students. The purpose of this study is to improve the acoustic quality of the classroom for a better learning process. Two classrooms at Faculty of Civil Engineering, Universiti Teknologi Malaysia have been selected for this study. Reverberation time is the most important factor in acoustics, which was determined using theoretical calculations and simulations. A Dass-21 of self-report questionnaires was used to measure the levels of depression, anxiety, and stress among the students.  The results showed that reverberation times of the classrooms were more than 1 second and 34% of the students have suffered from severe and extreme anxiety. The acoustic quality can be improved through the replacement of a painted concrete wall with high sound absorption material made of kenaf fiber in order to ensure reverberation time does not exceed the limit.

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