A Japanese text-to-speech synthesis technology is applied to a compact audio response unit (ARU) controlled by a personal computer. In this paper, the composition and features of the ARU are described. The ARU is composed of a voice synthesizer and a network control unit (NCU). The ARU is connected to a personal computer via a standard interface port. Access to a telephone terminal is carried out by control commands sent from a personal computer. Voice messages can be generated from Japanese text. Thus, a personal computer user can easily construct a compact audio response system by coding an application program and typing in text messages, to offer various telephone services.