
26
PART|I Signal Processing, Modelling and Related Mathematical Tools
3.1 INTRODUCTION
Text-to-speech (TTS) synthesis is often seen by engineers as an easy
task compared with automatic speech recognition
1
(ASR). It is true,
indeed, that it is easier to create a bad, first trial TTS system than to
design a rudimentary speech recogniser. After all, recording numbers
up to 60 and a few words (‘it is now’, ‘a.m.’, ‘p.m.’) and being able
to play them back in a given order provides the basis of a working
talking clock, while trying to recognise such simple words as ‘yes’ or
‘no’ immediately implies some more elaborate signal processing.
Users, however, are generally ...