Evaluation

Towards freely usable software for assesment purposes

Assessing speech synthesis is not as easy as assessing speech recognition, for various reasons:

• Various criteria can be used (do we assess speech intelligibility, or speech naturalness, or the efficiency of the speech component in a given application, etc.).
• It systematically requires subjective tests by human listeners, which makes assessment a heavy task.
• Assessing the overall quality of a TTS system does not often give interesting information on how to improve the system, since the output os the result of several complex and intermixed processes.

It is generally agreed that the developement of free software can boost assessment and improvement of technologies.

As far as speech synthesis is concerned, the community has made an excellent start in 1995-6 with Festival (and later FestVox) and MBROLA , but in order to push the technology forward faster we need more people involved to further build on these efforts. Other software tools are available for tests, like recently OpenMary, a multi-lingual (German, English, Tibetan) and multi-platform (Windows, Linux, MacOs X and Solaris) speech synthesis system.

HLT-evaluation.org

Another source of information on Speech Synthesis evaluation is the TTS page in the Human Language Technologies Evaluation web site.