[Problem] To provide an audio communication system in which a relaying device is connected to communication devices via a communication network, the communication devices being terminal devices, and the current location of each terminal device is managed by the relaying device.[Solution] this relaying device is provided with a network communication unit, a control unit, and a storage unit. The control unit divides the communication area of a communication network into a plurality of partial communication areas and stores, in the storage unit, location information indicating which partial communication area each terminal device is in. Upon a partial communication area specifying call from a calling terminal device, the calling terminal device being one of the aforementioned terminal devices, the control unit establishes a communication session in which the calling terminal device and terminal devices in the specified partial communication area participate, and audio signals received from terminal devices participating in the communication session are transferred by the control unit to the other terminal devices participating in the communication session.