Unit-selection text-to-speech synthesis based on predicted concatenation parameters

A method for unit-selection text-to-speech synthesis, comprising:

• at an electronic device having a processor and memory:
• receiving text to be converted to speech;
• generating a sequence of target units representing a spoken pronunciation of the text;
• determining, based on a plurality of linguistic features associated with each target unit of the sequence of target units, predicted statistical parameters for each of a plurality of acoustic features associated with each target unit, wherein a second acoustic feature of the plurality of acoustic features represents a change of a first acoustic feature of the plurality of acoustic features across a portion of a respective target unit of the sequence of target units;
• selecting, based on the plurality of linguistic features associated with each target unit, a plurality of candidate speech segments corresponding to the sequence of target units;
• for each candidate speech segment of the plurality of candidate speech segments:
• determining a target cost based on the predicted statistical parameters of the first acoustic feature associated with the respective target unit of the sequence of target units;
• and
• determining a plurality of concatenation costs with respect to a plurality of subsequent candidate speech segments, the plurality of concatenation costs determined based on the predicted statistical parameters of the second acoustic feature associated with the respective target unit of the sequence of target units;
• selecting from the plurality of candidate speech segments a subset of candidate speech segments for speech synthesis, the selecting based on a combined cost associated with the subset of candidate speech segments, wherein the combined cost is determined based on the target cost and the plurality of concatenation costs of each candidate speech segment;
• and
• generating speech corresponding to the received text using the subset of candidate speech segments.

A non-transitory computer-readable storage medium comprising computer-readable instructions which, when executed by one or more processors, cause the one or more processors to:

• receive text to be converted to speech;
• generate a sequence of target units representing a spoken pronunciation of the text;
• determine, based on a plurality of linguistic features associated with each target unit of the sequence of target units, predicted statistical parameters for each of a plurality of acoustic features associated with each target unit, wherein a second acoustic feature of the plurality of acoustic features represents a change of a first acoustic feature of the plurality of acoustic features across a portion of a respective target unit of the sequence of target units;
• select, based on the plurality of linguistic features associated with each target unit, a plurality of candidate speech segments corresponding to the sequence of target units;
• for each candidate speech segment of the plurality of candidate speech segments:
• determine a target cost based on the predicted statistical parameters of the first acoustic feature associated with the respective target unit of the sequence of target units;
• and
• determine a plurality of concatenation costs with respect to a plurality of subsequent candidate speech segments, the plurality of concatenation costs determined based on the predicted statistical parameters of the second acoustic feature associated with the respective target unit of the sequence of target units;
• select from the plurality of candidate speech segments a subset of candidate speech segments for speech synthesis, the selecting based on a combined cost associated with the subset of candidate speech segments, wherein the combined cost is determined based on the target cost and the plurality of concatenation costs of each candidate speech segment;
• and
• generate speech corresponding to the received text using the subset of candidate speech segments.