The Clue [Mic check]
The Answer TAP
The answer "TAP" fits the clue "Mic check" because tapping on a microphone is a common way to test if it is working. When you tap the mic, it creates a sound that lets you know if the audio is being picked up. This simple action is often used by performers before speaking or singing. So, "TAP" is a quick and effective way to check a microphone.