sort of binoculars, I'd guess. Probably trying to see and hear far.
If we are being serious now: I would guess that they were more blinkers than goggles, to stop you seeing rather than aid vision.
Close your eyes, you should see a marked improvement in your hearing.
Not sure if that is strictly true, but it does allow you to focus more fully on what you can hear without the distraction of your brain automatically analysing what you can see.

To be honest, I much prefer Elk101's theory.