POSITION DETECTION SYSTEM, AUDIO DEVICE AND TERMINAL DEVICE USED IN THE POSITION DETECTION SYSTEM

摘要

Provided is a position detection system capable of effectively preventing erroneous detection of audio to be measured. The position detection system includes a terminal device for inputting an audio signal from an audio device and a microphone. The audio device successively inputs measurement audio signals formed by two ore more audio signals of different frequencies to a speaker and receives a report signal indicating that the audio of the measurement audio signal has been collected from the terminal device. The audio device clocks a time t1, a time t2 between the output of the audio of the measurement audio signal from the speaker SP1 and the speaker SPn and reception of the report signals of the measurement audio signals by the signal reception unit and calculates the position of the microphone by using the time t1 and the time t2. For each frequency component of the measurement audio signal, when an audio signal exceeding a predetermined level is inputted from the microphone, the terminal device detects it as a component of the measurement audio signal and transmits a report signal upon detection of the measurement audio signal.