audio response unit (ARU)

Speech output systems, Audio Response Units (ARU), work with synthetic speech output.

Depending on the concept and use, they can respond to two-tone signals and output speech information via a voice user interface(VUI) depending on the keystroke. They may be host-basedsystems that retrieve their information from a database. Voice output systems can handle many requests with consistent quality at all times.

Voice output systems are used in call centers and IVR systems, Interactive Voice Response (IVR).