Abstract: A text-to-speech (TTS) system may be configured to incorporate breath sounds in the output speech. By incorporating breath sounds into speech output from text a TTS system may be able to mimic more naturally sounding human speech, particularly for long-form narration of text longer than short phrases. The breath sounds may be stored as units for unit selection or may be generated during parametric synthesis. The acoustic features of the breath sounds and duration between breaths may depend upon the punctuation of text, the linguistic distance between breaths, the breaks between intonational phrases, the linguistic context of the breaths, and other factors.