Text-to-speech

Speech synthesis generates human speech. TTS converts text to speech and is useful for a number of different applications. It is used in many places, including phone help desk systems and ordering systems. The TTS process typically consists of two parts. The first part tokenizes and otherwise processes the text into speech units. The second part converts these units into speech.

The two primary approaches for TTS uses concatenation synthesis and formant synthesis. Concatenation synthesis frequently combines prerecorded human speech to create the desired output. Formant synthesis does not use human speech but generates speech by creating electronic waveforms.

We will be using FreeTTS (http://freetts.sourceforge.net/docs/index.php) to demonstrate TTS. The latest version can be downloaded from https://sourceforge.net/projects/freetts/files/. This approach uses concatenation to generate speech.

There are several important terms used in TTS/FreeTTS:

• Utterance - This concept corresponds...