Most activities in mosque such as Friday prayer and the sermon by an Imam require
clarity of speech. Unfortunately, this ‘speech intelligibility’ performance is often poor due toinitial
design of a mosque. This paper presents assessment of the indoor acoustics of a mosque. Acoustical
properties such as reverberation time, clarity and early decay time are obtained from simulation data
using CATT indoor acoustic software. The studystarted with anempty mosque with no acoustic
treatment. Acoustic ‘green’ absorbers using micro-perforated panel (MPP) are then introduced to
improve the acoustic performance. The application of MPP is still rare for mosque and is expected
to replace the typical porous absorber. The effect of the panel size, location and frequency range of
sound absorption are simulated and the results are discussed