So, I shoot mostly in indoor ranges (unfortunately!) and I often run into two problems related to the noise.
First, my timer is sometimes triggered by a particularly loud neighbor. Any long gun (other than 22lr) in the lane next to me can set it off. Sometimes I can mitigate this by putting the timer in my shirt pocket, with the microphone against my chest. But if it's a 308 next door, I'm pretty much at their mercy. CCT125US has a good idea for this. From a different thread:
Another problem that comes up is hearing the beep. If a gun goes off right before the timer beeps, my muff's electronics cut off and I don't hear the beep. Or, I'll only hear the last .2s of the beep, and it throws my game. I've been working on going ahead with the drill if I hear those last .2s of the beep, just to throw a curve ball in my routine. But often I don't hear the beep at all. Not that big a deal, since I just restart the timer when I notice it, but it's pretty annoying because it happens frequently, because my muffs cut off even if it's a 22lr on the other side of the range. I've tried plugging my timer into my earpro's line in, but the electronics cut that off, too.
How do you all deal with these issues?