Love these zombie threads! :-)

For me this is a HYOH issue so long as not bothering others.

For short trips I can't see a reason to bother, and like some others have suggested, I'm out there to be more in tune with nature. For trips that are multiple weeks or months, however, I think that for many (most?) long distance hikers some sort of MP3 player is an excellent way to put your head somewhere different or adjust attitude, particularly good for long low-traffic road walks or "pretty boring" sections.

Can also be nice sometimes to put "normal world" stuff into your head; podcasts are good that way, and can help spark interesting topics of conversation.