Abstract: A polyphase digital filterbank extracts a spectral envelope composed of thirty-two bands, having uniform bandwidths, from a speech signal. The spectral envelope is then compressed into a predetermined number of bands having uniform bandwidths. Spectral energy features are extracted from the compressed envelope and are utilized to form templates representing the speech signal.

Abstract: A template-matching speech recognition system has a plurality of reference templates each having a plurality of addressable positions, each position storing a value corresponding to the probability of the occurrence of a particular binary value in a corresponding position in an utterance template for speech represented by the referenced template. A system bias template having a corresponding plurality of positions for storing values therein that are representative of the probability of the particular binary value occurring in a corresponding position of any utterance template. A match between an utterance template and a reference template is determined when the sum of the stored probabilities from the reference template positions, corresponding to the positions in the utterance template containing the particular binary value, exceed a predetermined threshold.

Abstract: A single board multiple option card for expanding the versatility of a host computer includes an onboard microprocessor, a digital signal processor and a switched memory device. The switched memory is accessible by the onboard microprocessor and the digital signal processor under the control of the onboard microprocessor. The card further includes an analog signal interface having a plurality of switches, the positions of which are controlled by the onboard microprocessor. As a result, multiple options are provided by varying the positions of the switches. Typically, such options may include: "Invisible Keyboard"; "Voice Command Over Telephone Lines"; "Voice Store and Forward Over the Telephone"; "Voice Record and Playback"; and "Hands-free Telephone".