Matsushita, the Japanese company that manufactures under the Panasonic and National brands, have developed a technique to provide a listener wearing headphones the feeling of 3-dimensional sound. Typically people wearing headphones think the noise is coming from the center of their head. The new technique involves modifying the sound to account for the transfer function of the ear canal, so that the listener thinks the sound is coming from in front.
Read the press release on the Matsushita web site.