Books deserve silence. From the lute playing of Peter Claire in Rose Tremain's Music and Silence to the lyricism of a single phrase in John Banville's The Sea, novels are full of music both explicit and inherent that demands the full attention of your imaginative ear.
Unfortunately, although my ideal reading environment is a sunlit corner accompanied by nothing but the sweet, Mozartian sound of my own blossoming enlightenment, I currently spend most of my time on overpriced trains full of people playing tinny Mark Ronson remixes on their mobile phones. So, dutiful member of Generation Jobs that I am, when I open my book I increasingly tend to plug into my little white music machine to block out the white noise. It's not ideal, but it lets me read, and I'm sure I'm not the only habitual listener/reader forced to treat masterpieces like lift muzak.