ihicahuaca.

Headword: 
ihicahuaca.
Principal English Translation: 

the chirp of a bird (see Molina)

Orthographic Variants: 
ihicauaca
Alonso de Molina: 

ihicauaca. (pret. oihicacauacaque.) gorjear las aues.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 36r. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

Breath is a part of this term, which seems significant, as does bird song across Nahua culture. Nahuatl hieroglyphs of birds very often show them with their mouths open, and some even show them with sound scrolls:
https://aztecglyphs.wired-humanities.org/content/cuauhtliztac-mh483r
https://aztecglyphs.wired-humanities.org/content/cuauhtlahtoa-mdz19r
https://aztecglyphs.wired-humanities.org/content/totonametl-mh536v
https://aztecglyphs.wired-humanities.org/content/tototl-mdz46r
https://aztecglyphs.wired-humanities.org/content/cuixtli-mh503r

themes: 
Animals, Bugs, Insects, Reptiles, Fish, etc.