Connect a vocal microphone to your PC for the best sound quality. If using an XLR microphone, connect an XLR-to-3.5mm adapter to the microphone and insert the 3.5mm plug into your "Line-In" port. You can also connect your microphone to an audio interface (external sound card) and connect the interface to your computer through the USB port.
Click the "Options" box near the upper left corner of your screen and select "Settings." In the left column of the pop-up menu, click the "Audio" tab.
Select the "Output" heading and choose any "ASIO" sound card from the list. If your computer does not already have an ASIO driver installed, you can download one for free from many sources online.
Click the "X" in the upper right corner of your pop-up menu to close out and return to your main project window.
Click your mixer, the smaller rectangular window on your screen that resembles a series of columns, or channel strips. If you cannot see your mixer, click the "View Mixer" button near the upper right corner of your screen.
Click any available channel strip on your mixer. This would include any column on which you have not already recorded audio. Right-click the square disk symbol near the bottom of the column to enable audio recording.
Click the "Metronome" button at the top of your screen and click the "Record" button, which resembles a black dot, also near the top of your screen. Record your vocals through your microphone as the metronome ticks in time with the beat, and click the "Stop" (square) button when you finish.