There are two key aspects to microphone problems in Skype: how your microphone connects to Skype, and how Skype sends your audio to another party. In investigating mic problems on Skype, begin with the former, but don’t rule out the latter. Sometimes the audio from a microphone gets messed up only when it reaches the other party’s computer.

Connection or Hardware?

The first step is to make sure the microphone itself works. You can accomplish this by either using a different microphone or taking your current microphone to another computer. Skype includes a Call Test Number in your contacts. After dialing this number, you’ll be prompted to record a message. It then plays back the message it received, enabling you to test the audio without the help of another person. If you feel your microphone isn’t the problem, look at the computer’s Internet connection. Try connecting the computer directly to the Internet via an Ethernet cable, if it’s not already. If the mic problems go away after switching to a wired connection, then the wireless connection might be too weak or congested to make the call. If you’re making a video call, reattempt the call in audio only. Video calls require more bandwidth than audio calls, and a lack of that bandwidth causes both the video and audio to stutter.

Speaker Issues

Separate computer mics can pick up audio from your speakers.
Separate computer mics can pick up audio from your speakers.

The problem may not be with your microphone. Many things can happen to an audio stream before it reaches your recipient’s speakers. Low Internet speed causes just as many problems for the other caller as it does for you. If you have persistent problems with one caller, have that caller dial the Call Test Number in his contacts. Your microphone should also turn off whenever it doesn't detect your voice. Otherwise it picks up the audio from your speakers. This creates an echo effect that can effectively shut down a conversation. A good way to fix or test this problem is to use headphones for the audio. By plugging in headphones you keep the audio from the other party from reaching the microphone.