
Cepstral offers 8KHz and 16KHz voices at a reasonable cost (when compared with other non-free solutions) and are compatible with the Festival project (see the Festival script on the Cepstral Support Pages.

(use the external links below to compare two systems). One might find that the most notable pro to using this commercial product, compared to a free solution, is the quality of the voices available. For general use, Swift's functions are comparable to that of Festival and other free solutions, allowing one to easily convert text to speech, and the ability to save that speech as an audio file (e.g.wav). Swift is a text-to-speech engine made by Cepstral allowing the user to convert text to computer generated speech.
