The vocalizations of Dwarf Vireo are very similar to, perhaps not distinguishable from, those of Black-capped Vireo (Vireo atricapilla) (Barlow 1980, Howell and Webb 1995).
The song of Dwarf Vireo is described as varied, and consisting of "rich to slightly scratchy, hurried warbling phrases, often prolonged, and short, scratchy, warbled phrases, whee chi-a-wee wee-chi, or wee ch'wee wee chir'-awee, or wi chee'r ch wit, etc." (Howell and Webb 1995).
For a representative audio recording with sonogram, see audio
As a general rule, there is close correlation in vireos between migration distance and the size of the song repertoire, with migratory species having larger repertoires (Mountjoy and Leger 2001); the repertoire size of Dwarf Vireo, however,is relatively large for a species that it is largely resident (Mountjoy and Leger 2001).
Calls of Dwarf Vireo include "a short, dry dri-dri-it or chi-chi chi-chi-chi, etc., like [calls of] Ruby-crowned Kinglet [Regulus calendula], a gnatcatcher[Polioptila]-like mewing meearr-meear, and a scolding cheh-cheh ... or jeh-jeh-jehr" (Howell and Webb 1995).