I found a nice parking spot just about 100 feet away from a beastly older looking yellow Whelen 3016 (siren D-11). Test time is 11AM and in the distance I heard a couple sirens go off, but nothing out of this siren (which was pointed right at me.) It made a couple of weird "boop" noises, like it was trying to do something. Here is a recording of what it did.
http://media.putfile.com/Siren-D-11
I'm wondering if this was something intentional, or it was the siren failing. All other sirens I heard in the distance were on a solid 3 minutes.