Here's an example and a question.
Example: Ever seen mythbusters? One time they tested ways to avoid being detected by a sonic device. The device would emit sound and measure the time it took to return. If the time was different than the time before, it set off the alarm. Know what one of the methods used to trick it was? A white sheet over the person. Now, if something is white, it reflects all wavelengths of light (what you are claiming to be sound). So something that reflects light should also reflect sound, but that doesn't happen in this case.
Question: If light is sound, why are being blind and being deaf independent of each other? A deaf person should be blind as a bat if light is sound.
First of all, the myth busters experiment was heat detecting, which is what a living body gives off as vibration or friction/sound. Just because you cannot hear it, doesn't mean it's not giving it out. A dog whistle should give you a clue as to our hearing against just that of a dog..
Also, being blind and deaf are only independent because our senses are primitive and we can only see and hear the frequencies of what the body is primed for.
A blind person has much better sense for sound than a person of perfect hearing, because the concentration is geared to one less sense in use.
Bats are blind but manage easily by using frequencies of sound.
Light is just the result of super agitation of matter.