Miming instrument playing is the equivalent of vocal lip sync, that is the musicians pretend to play their instruments to a prerecorded track of music. I was wondering--on so many mimed music videos on YouTube, musicians really seem to be playing their musical instruments that would create a sound. For example, the keyboard players such as Sergio Mendes are shown pressing his fingers down real hard on the keys and drummers are shown hitting the symbols real hard with their drumsticks. Wouldn't this cause an audience to hear additional sound while musicians perform in unison to the prerecorded music? If the answer is yes, do studio engineers afterwards wipe clean and delete the miming instrument playing for let's say a later television broadcast so all that you hear is the prerecorded track?