Tricolored Blackbirds sound a little bit like a Red-winged Blackbird that is being squeezed [note: we haven't actually squeezed one to verify this]. Their song is muffled and somewhat buzzy with no clear ringing notes. Both males and females sing, but female song occurs most often around the nest and consists of 3 rapid notes, while males sing from all corners of their territory to defend their space and to attract mates.
Male and female Tricolored Blackbirds give a short high-pitched squeak or a more muted, nasal squeak. They are often silent in flight, but sometimes give a short wuk that is lower pitched than a Red-winged Blackbird's flight call.