Radiotelephone voice control device, in particular for use in a motor vehicle

Abstract

The apparatus comprises a data memory containing a series of correspondents' call numbers and, for each call number, at least one associated voice print; a sound transducer suitable for picking up the name of a desired corespondent as spoken by the user of the apparatus; voice recognition means suitable for analyzing the correspondent's name as picked up by the transducer and for transforming it into an associated voice print; selective memory addressing means including associative means suitable for finding a voice print in the memory corresponding to the print supplied by the voice recognition means, and in the event of a match, for addressing the corresponding memory position; and means co-operating with the associative means for applying the addressed call number to the radiotelephone circuits. The voice recognition means evaluate and store a current noise level as picked up by the transducer in the absence of a speech signal; when in the presence of a speech signal, they subtract the previously evaluated current noise level from the signal as picked up; and then they apply the resulting signal as obtained in this way to a DTW type voice recognition algorithm with pattern recognition by dynamic programming adapted to speech using dynamic parameter extraction functions, in particular a predictive dynamic algorithm with forward and/or backward and/or frequency masking.