Push to hear?

[pboser]

Somewhere, but I can't remember where (I think maybe it was one of those museum self-guided audio tours), I used an audio device that had a microphone and a button on it, so you could push to hear someone talking to you. I think this could be a useful thing when listening - a lot better than yanking the Etys out of my ear when someone approaches. I'd think you could also add a little volume control to mix in outside sounds for safety (or family) purposes. Has anyone done something like this?
Thanks,
Pete

 

[jerb]

ou could wire up a normally open pushbutton switch to your ER4's but youd have to pass the signal through the switch so it wouldnt be the best idea