Have you ever wondered how external noise is eliminated when recording a song? The sound engineers' work has limitations, so, the need to have a microphone isolator is must in every recording studio.
Browse Musicians Friend Microphone isolation shield choices. They offer an array of products from well known manufacturers that guarantee the best results. Made from only the best foam materials to decrease external noise, giving excellent quality recording.
Now you know the purpose of those "accordion-looking" things in front of a microphone in a recording studio.