Now on a p sound move your hand slowly away a little and observe how that point of contact is concentrated on a small spot. Keeping the plane of the hand the same distance from your lips, slowly lower the hand so the spot moves to the tips of the fingers and finally, off the fingers. Go through the process again and then do it to the microphone instead. The idea, unless you re an aggro rapper, is to eliminate popping. Working in a group with individual mikes requires people to match as closely as possible their mouth to microphone distance.
Different proximity alters the quality as well as the volume of the sound.
Just because one person sings more loudly than the others, or more softly, doesn t mean that he or she should swallow the mike or move it out to arms length to compensate. It is the job of the sound operator to balance the voices. Sound checks are obviously important. Sound operators are notoriously uncommunicative. The volume on stage is your prerogative, not his.