The song of Red Warbler is intricate, and is described as "three forceful, clear notes...followed by a complex jumble of burrs, trills, and chips..." Phonetically, it resembles "cheevy-cheevy-cheevy . . petle-petle-petle, chur chur" or "chivy, chwvy chivvy, hu-r-r-r-r, chiv-chiv-chiv" (Elliott 1969).
For a representative audio recording with sonogram, see audio
The call is described as "a sibilant chi-ip or shee-ip, with the terminal syllable 'fussy' and rising in inflection" (Elliot 1969), and a "rather forceful but plaintive pseet" (Curson 2010).
No geographic variation in song or call has been reported.