DETECTION OF TDD SIGNALS IN AN AUTOMATED TELEPHONE SYSTEM

An automatic telephone answering system employs a switch activated by any of several techniques to select a language for communication with a caller. A single matrix determines the content of a message to be generated in response to input from the caller. A single matrix can be used because it is arranged in accordance with the content of the various messages and not on the specific language of the messages. All of the messages for each respective language are stored in a separate directory such that a given identifier obtained from the matrix will recall that message in the language determined by identification of the particular directory. A telecommunications device for the deaf (TDD) is treated in the same manner as a language and selection of messages employs the same matrix used for traditional languages. Received TDD signals are converted to ASCII for storage, and messages to be identified by the matrix are stored in ASCII and converted to TDD before transmission. Digital signal processing (DSP) techniques are used to recognize the transmission of TDD signals by a caller.