Disclosed is a method for controlling a cordless telephone device for use in a system that allows remote control of a home electric appliance. The method includes a first generation step of causing a first generation unit in a handset to encode audio input via a sound receiving unit in the handset to generate a first stream, and a first transmission step of transmitting the first stream to a base unit. The first generation step includes causing the first generation unit to generate instruction bit information and a first instruction stream when a first trigger indicating a request to start the remote control is given to the first generation unit. The first transmission step includes transmitting the instruction bit information and the first instruction stream to the base unit through a multiplexing scheme that is common to transmission of a first stream generated when the first trigger is not given.