To limit the probability that persons with hearing impairment will not be promptly notified of a fire situation, which could lead to delays in evacuation or moving to a safe place, which could lead to harm to these persons [Clauses 3.2.4.19.(1)(a) and 3.2.4.19.(1)(d)]
To limit the probability that persons will not hear or distinguish fire alarm signals from ambient noises and will not be promptly notified of a fire situation, which could lead to delays in evacuation or moving to a safe place, which could lead to harm to persons [Clauses 3.2.4.19.(1)(b) and 3.2.4.19.(1)(c)]