HT/5.1 system chirping

Lately,while watching some new DVDs I have noticed a "chirp" from various speakers.It is not coming from the same speaker each time.
I operate the Sony 9100ES in its' analog 5.1 into a Sony STR-Da 3000 receivers' "multi" channel inputs.
Any thoughts? Something preparing to "go"?
Thanks in advance to those who take the time to reply-Tom
While its hard to tell exactly what you mean I had a digital sound I could see being called a chirp that would come and go, for me it was turning off the DTS on DVD player so it didnt try to lock onto that signal but when mine happened you had to stop the movie......if yours is a subtle sound I doubt its the same issue.