We want to learn how different sensory signals are used by the human brain to generate representation or layout of a location.

BBC: CyberCarpet opens way to Pompeii

Any representation of the human form has traditionally been discouraged in Islamic art, helping Arabic calligraphy to thrive in its place.

BBC: The Koran through the ages

But audio experts say that the basic principles the CIA uses are likely the same ones that have driven the field of voice recognition since the 1940s: use of a spectrogram, a visual representation of the frequencies of human speech.

NPR: Bin Laden Tape Won't Raise Security Levels