An acronym for Vocal iPod Amplification syndrome: A condition in which someone listening to an iPod or mp3 player tends to speak much louder than they would without earbuds on due to the fact that they believe the people they are talking to cannot hear them over "the music". Generally occurs on public transportation, as road noise contributes additional background noise.
Derek: Hey man, what are you listening to?
Jake: TAYLOR SWIFT!
Jake: SORRY, I SAID I WAS LISTENING TO TAYLOR SWIFT. CAN YOU HEAR ME NOW?
^The above is a good example of someone with VIA syndrome