In 1985 the British Library National Sound Archive funded digital audio restoration research at Cambridge University, work that led to the prototype CEDAR computer, the earliest PC-based audio restoration system. Its unveiling at AES Europe in 1987, along with being featured on BBC TV’s “Tomorrow’s World” program, helped secure funding for a viable commercial system. Unlike other approaches, CEDAR gave users real-time control during the transfer, letting operators adapt the processes for varying noises in the material.
The first production systems in 1990 incorporated dual floating-point AT&T DSPs hosted in a conventional PC. The display here shows the world’s first first real-time spectral subtractive dehisser—known simply as CEDAR Dehiss. The System, comprising real-time Declick, Decrackle and Dehiss processing, had an end-user price of £60,000. This was eventually followed by dedicated hardware units, PC- and server-based systems and plug-ins for DAW platforms.
Since then, tens of thousands of CD, DVD, film and broadcast projects have employed CEDAR noise suppression technology, and in 2005, the company’s engineering directors were awarded an Academy Award in recognition of their services in this field. Twenty years after its founding, CEDAR Audio is still based in Cambridge, U.K., and retains its strong academic links with the university.