Aircraft Flight Operation Regulations Article 104
An airplane with a seating capacity of more than 60 but less than 100, shall have one battery-powered megaphone in the passenger cabin where it would be readily accessible to a normal cabin crew seat. For aircraft with a seating capacity of 100 passengers or more, two megaphones are required. One must be installed at the forward end and the other at the most rearward location where it would be readily accessible to a normal cabin crew seat.
中文原文 航空器飛航作業管理規則第104條
航空器載客座位數六十一座至九十九座者，應於客艙中配備電池供電之輕便擴音器一具；一百座以上者，應於客艙前後各配備一具，並置於客艙組員座椅周邊便於取用之處。