Males have two song types. The simpler is a variable series of 4 to 8 short, soft phrases. This is sung early in the nesting season and, once nesting has begun, shortly after sunrise and in territorial disputes. It may occasionally be sung on wintering grounds. More complex songs are sung from early morning to midday. These continuous jumbles of sharp chips, high-pitched whistles, and mewing notes are 10 seconds or more long and often include mimicked bits from the repertoires of jays, tanagers, towhees, vireos, warblers, sandpipers, and other species. Songs may be sung from elevated perches, while feeding, or while in motion.
Both sexes use high-pitched, nasal calls. A sharp, mewing zeee, or chay contact call is uttered in bursts of 2 to 6 notes about a second apart. A two note bee-beee version of this, with the first note slurred downward, seems to indicate mild agitation. Greater agitation provokes high pitched trills. They use a faster, louder, sharper version of the contact call in aggressive encounters. Mobbing calls are similar to these aggressive calls, but more urgent-sounding. Other calls include high-pitched whistles, a two-note hiccup used by the female during nest site selection, and isolated mimicry of other species.
Loud bill snapping is part of territorial defense and mobbing by both sexes. Snapping usually occurs when diving on an intruder from above or in fluttering aerial combat, often after bursts of aggressive calling.