Step 1. Enable the audio recording feature by selecting the microphone-alike icon.Most importantly, you need to unclick/disable the webcam and video recorder section from the main interface, click on the button and when you see the red "X" appear, it means the function has been disabled.
Step 2. Now you can click on the menu button under the microphone-alike icon to select the audio input: microphone or built-in input.
Step 3. Finally, click on "REC" button to start recording audio on Mac.