I have a 2006 Vibe with about 170k on it. For about 10,000 miles it has been occasionally making a strange noise when slowing down. The best I can do is describe it is 1 second of cow moooing if that cow was a bit more donkey than cow. Attached is my best cow-donkey hybrid impression of the noise. The noise comes from the front end.
When it does occur usually it is during the final downshift around 5-10 MPH. It happens about 25% of the time when coming to a stop. There is no clunk, no vibration, just a single iteration of the noise. On a rare occasion it will occur around 35-45 MPH right after I take my foot off the accelerator - again just a single iteration of the noise and no vibration or clunk. It only occurs when slowing down and it doesn't matter if the brake is applied or not.
Questions or more info requests are welcomed. I also don't mind critical review of my cowdonkey impression skills.
http://webpages.charter.net/campb292/mp3/Recording.mp3