This is the same effect for stage monitors or PA speakers. If you don’t have monitors and the title is quiet you can still hear your head tone, like singing bluegrass in the parking lot. But get on stage with a PA and if the sound is too low, your head tone and room tone can confuse your mind and you get lost between pitches and sing off key. So finding a sound level where you hear the band and your own voice louder than your head tone is important. Particularly because your head tone contains no room tone in when you are NOT in the mix. Like singing with hands over your ears, you hear a low bassy sound of your voice. In headphones, properly used, you are purposely hearing your room tone, over your head tone, AND also the band or tracks you are singing too.