Read the full story: http://www.businessinsider.com/booktracks-2011-8#ixzz1W9HU2dzc
Try it out here ... Download the iPad version of Sherlock Holmes
Unlike traditional audio books, Booktrack is a soundtrack that will match what you are reading, AS YOU READ (Note: no one is reading the story to you). You can now truly hear what it’s like to be back in Holmes time with the suspense of Dr. Watson helping Holmes solve a case, horse’s hooves beating against the pavement while the tension rises in the air, and when they sit before a fire you will hear the wood crinkling in the background as Holmes and Watson solve another mystery. The personalized sound effects and composition makes the story more powerful and immersive than it has ever been heard before!View a trailer for Sherlock Holmes Speckled Band Booktrack:
So basically, it enhances your reading experience, by providing sound effects, and a "score" as you would be hearing if you were watching the movie instead of reading. Interesting idea, don't you think?