Improvements in Speech Synthesis – COST 258: The Naturalness of Synthetic Speech

Why is this so, and what can be done about it?

Prosodic processing must be rendered more varied and more appropriate to the speech situation
• Timing, melodic control and the relationships between the various prosodic parameters need increased attention
• Signal processing systems must be developed and perfected that are capable of generating more than just one voice from a database
• A better understanding must be achieved of what distinguishes one voice from another, and of how speech styles differ between simply reading aloud numbers and sentences and their use in interactive speech
• New evaluation methodologies should be developed to provide objective and subjective measurements of the intelligibility of the synthetic speech and the cognitive load imposed upon the listener by impoverished stimuli
• Adequate text markup systems must be proposed and tested with multiple languages in real-world situations
• Further research is required to integrate speech synthesis systems into larger natural-language processing systems