16. A non-transitory computer-readable storage medium storing processor-executable instructions for controlling a computing device, comprising: program code to receive text data; program code to determine a sequence of linguistic units corresponding to the text data, the sequence of linguistic units comprising a first linguistic unit and a second linguistic unit; program code to generate a representation of the first linguistic unit using a model for the first linguistic unit and a first parametric speech synthesis technique, wherein the first parametric speech synthesis technique comprises synthesizing speech using a computerized voice generator; program code to retrieve a pre-recorded speech unit for the second linguistic unit from a unit selection database, wherein the pre-recorded speech unit comprises recorded speech configured with acoustic properties consistent with speech generated by the first parametric speech synthesis technique; program code to concatenate the representation of the first linguistic unit and the pre-recorded speech unit for the second linguistic unit to generate audio data; and program code to cause audio corresponding to the audio data to be output using an audio speaker.
16. A non-transitory computer-readable storage medium storing processor-executable instructions for controlling a computing device, comprising: program code to receive text data; program code to determine a sequence of linguistic units corresponding to the text data, the sequence of linguistic units comprising a first linguistic unit and a second linguistic unit; program code to generate a representation of the first linguistic unit using a model for the first linguistic unit and a first parametric speech synthesis technique, wherein the first parametric speech synthesis technique comprises synthesizing speech using a computerized voice generator; program code to retrieve a pre-recorded speech unit for the second linguistic unit from a unit selection database, wherein the pre-recorded speech unit comprises recorded speech configured with acoustic properties consistent with speech generated by the first parametric speech synthesis technique; program code to concatenate the representation of the first linguistic unit and the pre-recorded speech unit for the second linguistic unit to generate audio data; and program code to cause audio corresponding to the audio data to be output using an audio speaker. 19. The non-transitory computer-readable storage medium of claim 16 , wherein the unit selection database was created using recorded speech and the model for the first linguistic unit was created using at least a portion of the recorded speech.