If you’re a regular concert goer, and you happen to either be close enough to the stage or own a pair of opera glass or good birding binoculars, you’ve noticed those portable plexiglass things scattered about different parts of the stage. Mostly they’re located at the back of the cello and second violin sections, and behind the woodwinds, and between the timpani and the trumpets. Why are these unsightly things on stage in the first place?
Because when you’re exposed to sudden high sound pressure levels, you lose parts of your hearing, and eventually much of it. It’s also quite difficult to produce a good sound, especially as a wind or brass player, if you have earplugs in, because you mostly only hear the sounds your mouth is making, not what is coming out of the end of your instrument. So in come these contraptions that often serve as a band aid on a giant open wound.
Basically, there are three major sonic “death zones” on our stage: (1) between the percussion and the woodwinds and second violins, (2) all around the timpani, and (3) between the brass section and the back of the lower string sections. See the helpful (and hopefully dramatic) illustration below:
