System with the first handset and with another handset

摘要

System with a first handset and with a further handset, the first handset having a first control and the further handset having a further control, the first handset having a light transmitter which can be controlled by the first control, the first handset having a sound transmitter, which can be controlled by the first controller at the same time as the light transmitter, the further handset having a light receiver which is connected to the further control, the further handset having a sound receiver which is connected to the further control, the further control for determining the the time difference between the arrival of a sound signal emitted by the sound transmitter at the sound receiver and the arrival of a light signal emitted by the light transmitter at the light receiver is suitably designed.