Transfer device, transfer method for transferring sound signals in different communication systems

A transfer device comprising:

• a first reception circuit that receives a sound signal destined to a second terminal device in a second communication system supporting one way communication from a first terminal device in a first communication system supporting two way communication;
• a first transmission circuit that transmits the sound signal received in the first reception circuit to the second terminal device;
• a second reception circuit that receives a sound signal destined to the first terminal device from the second terminal device;
• a second transmission circuit that transmits the sound signal received in the second reception circuit to the first terminal device;
• and
• a storage circuit that stores the sound signal received in the first reception circuit if the second transmission circuit is transmitting the sound signal received in the second reception circuit,
• wherein if the sound signal is started to be stored in the storage circuit while the second transmission circuit is transmitting the sound signal received in the second reception circuit, the second transmission circuit reduces a speech speed in transmitting the sound signal received in the second reception circuit, the first transmission circuit transmits the sound signal stored in the storage circuit when reception of the sound signal in the second reception circuit is completed, and the second transmission circuit adjusts the speech speed so that a point of time when transmission of the sound signal received in the second reception circuit is completed approximates a point of time when transmission of the sound signal in the first transmission circuit is completed.