A speech synthesizer that synthesizes speech by actuating a voice source and a filter which processes output of the voice source according to speech parameters in each successive short interval of time according to feature vectors which include formant frequencies, formant bandwidth, speech rate and...http://www.google.com.hk/patents/US4896359?utm_source=gb-gplus-share專利 US4896359 - Speech synthesis system by rule using phonemes as systhesis units
