I figure this is a rather strange question, however, I noticed this quite some time ago and wanted to make sure that this is in fact a permanent condition before posting.
The situation is as follows:
Whenever I put in both my in-ear headphones I notice that my nasal breathing resistance increases by quite a bit after some seconds have passed. The effect reverts itself about 30 seconds past removing the in-ear headphones.
Fellow divers will know how differences in breathing resistance feel like, as you can adjust it on most regulators, but for everyone else you could try breathing through a straw or something (though it's not that extreme).
The oral breathing resistance is not affected however.
My nasal breathing resistance is also not increased when wearing only one in-ear bud or using a normal headset (like with a frame, etc.).
Basically the increased breathing resistance leads to a feeling of not "having enough air" and is rather displeasing. It is not as bad as suffocating, but like halfway between breathing normally and drowning.
Does anyone know of such a phenomenon or what causes it?
Thinking about it, I think the whole thing started after I got into diving a couple of years back.
Could it be an unconscious reaction to the auditory canal being sealed off or something? Or an unconscious activation of my "diving mode"?
I remember that I never had any problems "closing off" my nasal breathing when being underwater and not having a mask on, I just automatically switched to oral breathing (which I never use in daily life, except when doing sports). The instructor said that this was rather uncommon and that most people have to actively force themselves to not breathe though the nose when diving without a mask (at least at the beginning).