The material generally used for sound proffing of rooms like a recording studio and auditorium, etc. is

Options

A. cotton
B. coir
C. wood
D. styrofoam

Explanation

The material generally used for sound proofing of rooms like recording studio, cinema hall, auditorium which absorb sound and facilitate in proofing is styrofoam. Ear plugs (device used by working person of commercial and industrial zone) are made up of very fine glass wood or cotton wood impregnanted with while ear muffs contain fluid seals or plastic foam for absorbing sound.