LAST EDITED ON 03-06-06 AT 10:03 PM (EST)Adding spoiler space for Season 3 (?) of 24, please don't scroll down if you plan to watch it...
.
.
.
.
.
.
.
.
.
.
.
.
.
I know they've done it a couple times before. The one I remember best was the Ryan Chapelle shooting, I am pretty sure it was silent. I also believe when David Palmer was poisoned by Mandy, it was a breathing final countdown
But damn, why Edgar. Waaaaaaaaaah
ETA: Here are the "different" beep occurences
1.23: Nina is revealed as the CTU Mole and the tempo was different
1.24: Teri's death warranted the silence
2.??: Mason flew the plane with the nuclear bomb (?) in it into the desert
2.24: David Palmer is poisoned by Mandy, a gasping final few seconds
3.18?: Ryan Chapelle is shot by Jack Bauer to satisfy terrorist
5.13: Edgar Stiles dies due to nerve gas
Bob Factoid: The fishercat is the only creature known to have gone completely insane chasing its own tail.