One-bit wonder

Inventors often complain that politicians know nothing about technology. But
former Australian prime minister Paul Keating proved otherwise when he invested
in Lake Technology. Now the company’s co-founder David McGrath has been granted
US patent 5 990 818. It describes a way of converting an audio signal into a
stream of single bits, which can be amplified without loss of quality because it
shifts any noise to a frequency too high to be audible. The technology has been
licensed to Sharp (New Scientist, 24 July 1999, p 10) and Dolby
Laboratories.