WIDEBAND SPEECH SYNTHESIS FROM A NARROWBAND SPEECH SIGNAL

摘要

Wideband speech is synthesised from a bandlimited speech signal, for example from speech which has been transmitted via the public switched telephone network. Due to the nature of the vocal tract, there is a correlation between a bandlimited signal and those parts of an original wideband speech signal which are missing from that signal. In this invention narrowband speech is characterised in terms of estimated formant frequencies provided by a peak picker (2). The frequency of formants in speech give a good indication, for voiced sounds, as to the shape of the vocal tract. The set of frequencies provided by the peak picker is used to access a codebook (4) which provides synthesis parameters for use by a synthesiser (5).