contributions on Context Adaptive Training with Factorized Decision Trees for HMM-Based Speech Synthesis

Speech synthesis vs. speech recognition

As mentioned in the original paper, speech synthesis requires a much larger and more complex set of contexts in order to achieve high quality synthesised speech. Examples of such contexts are the following:

• Identity of neighbouring phones to the central phone. Two phones to the left and the right of the centre phone are usually considered as phonetic neighbouring contexts
• Position of phones, syllables, words and phrases w.r.t. higher level units
• Number of phones, syllables, words and phrases w.r.t. higher level units
• Syllable stress and accent status
• Linguistic role, e.g. part-of-speech tag
• Emotion and emphasis