https://www.youtube.com/watch?v=cM5b0r-QCwk
**Disclaimer: This is not my video.** Also, turn down your volume!
The Federal Signal siren model heard in is video is a 2001-130, which was installed sometime last year. Most of us are aware of the known "sound pitch variation" issue with that particular model. This one, however, sounds like it could be experiencing another problem. Thoughts?