There seems to be a bug with the new digital watches that spawn on zombies.
Sometimes a dead zombie with a watch will have the alarm already set, when the alarm goes off it will make the alarm noise. Picking up the watch and resetting the alarm will not make the noise go away. If you pick up the watch and move it somewhere else, the noise will continue at the spot where the zombie died. If you move the corpse, the noise will continue at the spot where the zombie died. Nothing you can do in game seems to make that noise go away, if you leave the area and return the noise will play again.
As you can imagine it's super annoying, especially if the watch is near your safehouse
I don't know if it's significant or not but both times this happened to me were at the spot with the 2 picnic tables just east of the large warehouse on the north end of Muldraugh.
I managed to make the noise go away by removing the AlarmSound event from the digital watch entry in the newitems.txt file. This means you can't hear the watch alarm, but I assume the zombies will. So until it's fixed, this is a temporary solution if this happens to you and the watch alarm noise is making you crazy
Also this is my first post, enjoying the game immensely so far. Great job!