Data from: The breath shape controls intonation of mouse vocalizations

Intonation in speech is the control of vocal pitch to layer expressive
meaning to communication, like increasing pitch to indicate a question.
Also, stereotyped patterns of pitch are used to create distinct sounds
with different denotations, like in tonal languages and, perhaps, the ten
sounds in the murine lexicon. A basic tone is created by exhalation
through a constricted laryngeal voice box, and it is thought that more
complex utterances are produced solely by dynamic changes in laryngeal
tension. But perhaps, the shifting pitch also results from altering the
swiftness of exhalation. Consistent with the latter model, we describe
that intonation in most vocalization types follows deviations in
exhalation that appear to be generated by the re-activation of the
cardinal breathing muscle for inspiration. We also show that the brainstem
vocalization central pattern generator, the iRO, can create this breath
pattern. Consequently, ectopic activation of the iRO not only induces
phonation, but also the pitch patterns that compose most of the
vocalizations in the murine lexicon. These results reveal a novel
brainstem mechanism for intonation.