How to Run a Clean Microphone Test Before a Call, Stream or Sale
A microphone should be judged by both level and clarity. A moving meter is not enough if the recording is muffled, distorted or routed through the wrong device. Record a short phrase, play it back and repeat after changing distance or input device.
Set up the room first
Turn off loud fans, place the device on a steady surface and move the microphone away from rubbing sleeves or keyboard noise. A quiet setup makes it easier to tell hardware problems from environment problems.
If you are testing a phone, try both handheld distance and table distance. Small microphones can sound very different depending on position.