Do you mean your own personal sound file or a certain piece of music? If just music from a band try searching the music area of site for the band/muscician you like and when their page loads it should have a media player playing some samples of their music. If you click add to the right of the song title it will allow you to add that song to your profile. That's the best and easiest way to add sound to your profile but if it's something personal and not music like that then am not the best for advice on that end as been ages ssince I last used any sort of music on any of my sites.
