Until now the criteria used in the design of a mosque sound reinforcement system are mainly based on criteria for religious building well accepted in the West. Accurateness and effectiveness of the theory and criteria being using cannot be upheld as the end users often could not accept the end product. it is appreciated that mosque and churches have fundamentally different acoustic requirements. This research was conducted primarily to identify design criteria for sound system that will be accepted by the local mosque congregation. The criteria investigated were the ambient noise disturbance level due to fan and pink noise, the most acceptable speech loudless level due to fanwith an optimum intelligibility at various ambient noise levels, the Haas (localization) effect and the percentage disturbance due to delay time and the difference in primary over secondary loudness level. In addition, the acoustic characteristics of the mosque of the UTM Kuala Lumpur and the characteristics of the sound system installed to enable this research to be conducted were elaborated on in this thesis. Analysis of the data gathered was done using the Statistical Analysis System (SAS) package available at UTM Computer Centre. The statistical analysis discussed includes varieties correlation coefficients, variates mean value, standard error, 95% confidence interval, Duncan multiple range test, T-test, coefficients of variations (CV), linear and nonlinear mathematical modelling of the variates under study. Based on the mathematical model obtained, prediction was made on the ambient boise level that would procedure peaceful and serenity environment inside the mosque. The most accepted speech loduness level with an optimum speech inteligibility for various ambient noise level with optimum speech intelligibility for various ambient noise level was also predicted. The results indicated that, for optimum intelligibility, speech level of at least 3 dB(A) above the most accepted speech loudness level is required. For the Haas effect, the loudspeeker arrangement plays a significant role, as it was fou theat the decentralised loudspeeker arrangement was able to provide realism more effectively. The percentage disturbance found in this study significantly indicated that higher level of disturbance as compared to the Haas findings. It was indicated also that, the exixtence of any echo cannot be tolerated. it is essential to ensure that the speech is heard to come mainly from the primary source. The implicit functions of the sound system design acceptance criteria also being contributed by the room acoustic characteristics. As such, further research is required to ascertain the actual implicit function for the sound system design acceptance criteria.