Use a different microphone
You can use an external microphone for chatting with friends, speaking with colleagues at work, making voice recordings, or using other multimedia applications. Even if your computer has a built-in microphone or a webcam with a microphone, a separate microphone usually provides better audio quality.
If your microphone has a circular plug, just plug it into the appropriate adapter on your computer. Most computers have two adapters: one for microphones and one for speakers. Look for a picture of a microphone next to the adapter. Microphones plugged into the appropriate adapter will usually be used by default. If not, see the instructions below for selecting a default input device.
If you have a USB microphone, plug it into any USB port on your computer. USB microphones act as separate audio devices, and you may have to specify which microphone to use by default.
Select a default audio input device
Click the sound menu on the menu bar and select Sound Settings.
On the Input tab, select the device in the list of devices. The input level indicator should respond when you speak.