Step 1. Select "Audio Recorder" from the main interface and choose the audio source that you would like to record sound from, such as system sound or microphone.
Step 2. Click at the "Output" setting icon, scroll down and choose M4A from the "Audio format" section.
Step 3. Click at the "REC" button to begin the recording process. You can adjust the volume of the sound while recording.
To finish the recording, click at "Stop" button and you will be able to preview and save the recording on your Mac.