Interpretations:Doctor Worm (Live Almanac)
The way I hear it, Doctor Worm is a drummer who wants to emulate those artists that use stage names like Dr. Dre and such. But he's not a very good drummer, and he freely admits it, so he chooses a stage name that sounds like his heros, but also reflects his lowly status as a beginner. He's getting better, but he needs the praise of others to motivate him to continue learning. Being the straightforward and honest type, he asks folks to come and critique his style, hoping for praise, but willing to accept advice on how to improve.
His stage name is Doctor Worm, and in an effort to identify with his persona, he claims that he can't hear the doorbell. Worms don't have ears, so, they cannot hear airborne sounds. Or perhaps, he practices the drums loudly enough they drown out the sound of the doorbell. The common drummer's practice of wearing earplugs may contribute to his inability to hear the doorbell.
His friend Rabbi Vole (also a beginner) has also chosen a title above his ability, but a name that reflects his current ability. And in the neieve (sp?) way beginners have, has chosen a honorific that isn't commonly used among musicians.
All in all, I think Dr. Worm is a refreshing song about how we all kinda make it up as we go along, with varying degrees of success.