title: Assessment of noise levels in 200 Mosques in Riyadh, Saudi Arabia.
abstract: BACKGROUND
  Noise-induced hearing loss (NIHL) is a recognized concern within the context of occupational and general health. However, noise levels are seldom studied at nonworkplace and nonabode sites that are visited regularly, e.g., places of worship. The purpose of this study was to assess the noise levels inside and outside of mosque prayer rooms and to compare the levels with established noise tolerance limits.
  
  
  METHODS
  A portable digital sound level meter was used to determine the noise level (measured in dB) inside and outside of mosque prayer rooms. The highest (peak) and lowest noise levels from each recording were tabulated. Statistical analysis was performed using a two-tailed Student's t-test (alpha = 0.05).
  
  
  RESULTS
  Noise levels were measured at 200 mosque prayer rooms from all 15 municipal districts of Riyadh, Saudi Arabia. Of these, 151 prayer rooms (75.5%) had both inside and outside noise measurements and the remaining 49 prayer rooms (24.5%) had only inside noise measurements. There was significantly greater noise outside compared to inside the prayer rooms, for both the highest noise level (outside: 87.8 ± 4.8 dB compared to inside: 85.8 ± 5.4 dB, P < 0.0001) and lowest noise level (outside: 58.4 ± 3.8 dB compared to inside: 56.6 ± 3.6 dB, P < 0.00001). In all, 112 of the inside highest level measurements (56%) and 113 of the outside highest level measurements (74.8%) were greater than 85 dB, the sound level at which NIHL has been shown to occur in occupational settings.
  
  
  CONCLUSIONS
  A large proportion (56%) of mosque prayer rooms with inside peak noise measurements were above acceptable levels (85 dB), however, prayers certainly do not last for 8 continuous hours. Therefore, the level of noise at mosques is acceptable and in compliance with international norms of hearing safety; moreover, it does not present any risk to hearing in the long run.
authors.affiliation: Medical College, King Saud University, Riyadh, Saudi Arabia.
authors.forename: S A
authors.initials: SA
authors.lastname: Al Shimemeri
authors.forename: Chirag B
authors.initials: CB
authors.lastname: Patel
authors.forename: Al Fayez
authors.initials: AF
authors.lastname: Abdulrahman