I only change my needle if i broke the tip, you can hear it, it is a different sound somehow louder and funky.

Oh I forgot to reply to this earlier, I have that light, I did move it from the back to the side. It didn't leave any marks on my machine...but the bendy part sometimes seems to not hold where I put it. :| The light itself is nice and bright. Although I don't think I would spend the money again for one.