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 audio socket on your computer. Most computers have two sockets: one for microphones and one for speakers. This socket is usually light red in color or is accompanied by a picture of a microphone. Microphones plugged into the appropriate socket are usually 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
Open the Activities overview and start typing Sound.
Click on Sound to open the panel.
In the Input section, select the device that you want to use. The input level indicator should respond when you speak.
You can adjust the volume and switch the microphone off from this panel.