Method and apparatus for altering voice characteristics of synthesized speech

摘要

Method and apparatus for altering the voice characteristics of synthesized speech to obtain modified synthesized speech of any one of a plurality of voice sounds from a single applied source of synthesized speech, wherein the method relies upon the simulation of an adjustment in the sampling period of the digital speech data from the single applied source of synthesized speech based upon the inequality between first and second reference factors, thereby altering the vocal tract model of the digital speech data to a preselected degree. At the same time, the predetermined pitch period and the predetermined speech rate of the source of synthesized speech remain unchanged. Thus, the altered vocal tract model of the digital speech data from the source of synthesized speech is accompanied by the original pitch period and speech rate of the synthesized speech source in producing modified digital speech data having voice characteristics which are altered with respect to the voice characteristics obtained from the original source of synthesized speech. An audio signal representative of human speech is generated from the modified digital speech data, with the audio signal being converted into audible synthesized speech having voice characteristics different from the voice characteristics of the original source of synthesized speech. Specifically, the altered voice characteristics of the synthesized speech, while capable of being interpreted as coming from a person of different age and/or sex are generally of a quality to be regarded as non-human in origin based upon the audible sound thereof so as to supposedly originate from fanciful or whimsical sources, such as talking animals, birds, monsters, etc.