Design and construction of a talking call line identification unit

Most electronic devices convey information to the user by displaying it on a liquid crystal display (LCD). Visually impaired people cannot benefit from using electronic devices with LCD technology. Adapted products exist, but because no market for these products has been established, relatively small numbers are imported. Therefore, only a few useful products are available at an affordable cost. We present the design and construction of a talking call line identification (TCLI) unit with integrated sound output to be used on Telkom lines. This unit incorporates audio and visual input/output of all on-board functions. Visually impaired users can navigate the unit settings assisted by prerecorded voice prompts and big input buttons. A graphical LCD unit completes the unit, so that it can be used by the non-impaired. The reproduction of a human voice is accomplished by prerecording on a solid-state information storage device (ISD) that is capable of recording eight minutes of voice data. This enables the unit to announce the incoming caller´s number or an associated recording of the caller´s name and comes as a great benefit not only to the visually impaired, but to seeing users of telephones as well