An orgasm that is induced by a sound, music, or theoretically by words. Does not necessarily involve the genitals, however it is possible for the auditory pathways of the brain to transmit the orgasm "wave" to other pleasure centers of the brain. Thus causing a potentially embarrassing public display of knee buckling, moaning and ejaculation. The physiological process is not entirely understood but it is theorized that it has something to do with neuron pathways that crossed during fetal development.
Dude, I was totally listening to Stone Temple Pilots and it was a total sonic orgasm, I wish it were that easy to get a chick off!