Just a thought: the inside of your mouth is rather hearing sensitive. This is obvious when a dental professional is working on your teeth, or even if you simply tap one of your front teeth with your fingernail. This sound is not being perceived through your ear holes. Or try covering your ears and making a “P” sound with your lips. There is input from inside your mouth when you’re playing, and I’m guessing that this may be affected by the kind of mouthpiece you’re using. In any case, what you hear while playing is somewhat different from what you hear when you listen to a recording of your playing.