The common alarm calls of the Warbling and Red-eyed Vireo are quite similar. These recordings were made on the same day at Palmyra, NJ in early July, of presumed breeding birds. Note the call of the Warbling Vireo becomes louder towards the end and is longer than the call of the Red-eyed Vireo, which is shorter and descends at the beginning, creating a more whiny sound.
Warbling Vireo (with Gray Catbird mew towards end).
Calls made by a Red-eyed Vireo chasing a Blue Jay (July, PA).
Warbling Vireos give a marsh wren-like tuk call during interactions, the call often being given in flight as with this example where a male chased another Warbling Vireo (May, NJ).
Another example (June, PA).
The twitter call is a rapid series of these calls, but a little higher-pitched, usually given early in the breeding season during territorial conflicts, per BNA.
(early May, NJ)
reduced time scale
Tuk calls by a calling juvenile Warbling Vireo (July, NJ).
This agitated Philadelphia Vireo made similar calls (July, ME).
The Blue-headed Vireo alarm call is a repeated scolding that varies in intensity and speed (July, ME)
A faster version (July, ME)
These soft contact calls were being given by a family group. I couldn't determine which birds (parents or juveniles) were giving the calls (July, ME).
The White-eyed Vireo has a scolding call that is similar to that of the Blue-headed Vireo (May, NJ).
Soft calls by a Yellow-throated Vireo, including the alarm call (May, ND).