What is the thing in front of a mic in a studio?

Answer 1

a pop filter

The pop filter is a screen, typically round in shape, that redirects or "filters" the plosive sounds such as p's and b's k's and t's. When pronouncing words which have these sounds such as in "Bob pretty much likes to play Baseball." the B, P, CH, and K sounds cause the microphones membrase to overvibrate cause a distortion or "popping" sound.

The filter also helps somewhat for "essing" or the hiss sound made by pronouncing s's and sh's and ch's.

Pop filters either suppresses the plosive breath (such as when using foam cloth or nylon) or with some angular cut holes, redirect the sound away from the mic. Filters can be bought manufactured, or can often be made from items such as stretching nylon (as from hosiery) over a frame and setting in front of the mic.

With practice, the speaker/singer learns how close the filter should be to the mic and how close the mouth should be to the filter to give the best audible sound but yet filter out the pops most effectively.