B011 Elderly fire alarm

Optimum sound pressure level of a fire alarm sounder for elderly

Brief:

Some building occupants cannot hear the activated fire alarm nor can they recognize the alarm, although the fire alarm system has been installed. This study reports the subjects ratings on the fire alarm audibility in terms of sound pressure level (SPL) by 230 awaken subjects divided by 2 age groups (22-48 and 66-88) in the 5 elderly care centres. A higher perceived SPL is preferred for the elder age group to obtain the same subjective rating, when compared with the younger age group. Correlations between the subjective ratings and the measured SPL show that the alarm SPL of 65 dBA can alert most of the awaken occupants in daytime, but expressed a preference that the alarm SPL should be increased. The results show that the optimum fire alarm SPL is 74.5 dBA, which is very close to the recommended alarm SPL at bed head of 75 dBA in the design guidelines. The preferred SPL of occupants should be considered in designing a fire alarm system for elderly.

Further Information:

Wong LT, Leung LK, 2004. Optimum sound pressure level of a fire alarm sounder for elderly, Proceedings of Shenyang-Hong Kong Joint Symposium 2004 on Healthy Building in Urban Environment, 29-30 July, Shenyang, China, pp. A103-A110.