Music For Deaf People

There is often someone doing sign language on the music channels late at night. It's quite funny, particularly when 'I Predict a Riot' by the Kaiser Chiefs comes on.

I suppose that deaf people can 'listen' to music if the song consists of entirely of bass frequencies. This might allow them to physically feel certain elements of a piece of music as opposed to hearing it.
 
I've seen the guy who does sign language for MTV on Base at 5am. I wonder how many deaf people watch MTV Base at 5am?