How loud should the sound level be in the mosque?

The sound level of the mosques' inner and outer speakers is a source of dispute and debate in Saudi Arabia. The objectives of this research were to evaluate the sound level and the population's opinions in Riyadh mosques so that a suitable sound level can be recommended. The study utilized a sound level meter to measure the sound level of 20 randomly selected mosques in Riyadh and a questionnaire for opinions gathering about the loudness of the mosque's inner and outer speakers of a random set of worshipers and neighbors of the 20 mosques. The inner sound level was measured in 5 horizontal locations in every mosque while having two vertical locations, ear height and seating ear height, for each. The sound level was also measured outside each mosque. The results showed that the minimum, maximum and average for the inner and outer sound levels (in dB) of the mosques were (71.42, 87.24, 77.74) and (60.19, 76.46, 68.95) respectively. The results showed statistically significant differences between the inner sound levels among mosques (p=0.000, F=7.47) and between the outer sound levels among mosques (p=0.000, F=76.10). No statistically significant effects were found for the height (p=0.979) and horizontal location (p=0.11) inside the mosque on the sound level. 9.6%, 57.7% and 32.7% of 52 worshipers rated the inner sound level as low, medium and high respectively. With respect to outer sound level rating, the percentages of low, medium and high were 17.3%, 46.2 and 36.5% respectively. The age effect on the worshipers' opinion of the inner and outer sound levels was not statistically significant (p=0.39 and p=0.17 respectively). The study could not find any standards for the sound level of the mosque's speakers. Furthermore, the sound levels varied significantly among the studied mosques. There is a need for implementing suitable standards for the sound levels of mosques' speakers so that the objectives of the mosque's sound systems are reached, namely: clear and safe auditory message. It is recommended that the sound level to be set as a standard should not exceed the levels recorded in this research.