CANBERRA - A new study released on Wednesday has found some Australian birds are changing the way they sing, so they can be heard over traffic noise.

The study conducted by researchers of University of Melbourne compared the songs of Silvereyes living in cities and rural areas, and found Silvereyes in urban areas sang songs more slowly and at a higher pitch.

According to Senior research fellow Kirsten Parris, the findings showed city noise may affect the birds' breeding.

"Both these changes that we've seen, singing higher and singing more slowly, may on the face of it make the song less attractive to females," she told ABC News on Wednesday.

"Basically the birds are presented with a trade-off between being heard at all and having the females like what they hear."

The Silvereyes is a very small passerine bird native to Australia, New Zealand and the south-west Pacific islands of Lord Howe, New Caledonia, Loyalty Islands, Vanuatu, and Fiji.