Self-monitoring for headphones is the flexibility to listen to your self via your headphones when you’re recording or performing. This may be useful for staying in time and pitch, and for listening to how your voice or instrument sounds within the combine.
Many audio interfaces and mixers have a built-in self-monitoring characteristic. To allow self-monitoring, you will usually want to attach your headphones to the headphone output of your audio interface or mixer, after which activate the self-monitoring swap or knob.