Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site alice.UUCP
Path: utzoo!linus!decvax!bellcore!petrus!scherzo!allegra!alice!ark
From: ark@alice.UucP (Andrew Koenig)
Newsgroups: net.audio
Subject: Re: white noise on CD's
Message-ID: <4405@alice.UUCP>
Date: Tue, 8-Oct-85 20:59:41 EDT
Article-I.D.: alice.4405
Posted: Tue Oct  8 20:59:41 1985
Date-Received: Fri, 11-Oct-85 06:38:54 EDT
References: <766@charm.UUCP>
Organization: Bell Labs, Murray Hill
Lines: 17

>> I don't know if it is true, but my roomate has informed me that the manu-
>> facturers of CD's introduce white noise (maybe pink noise) to reduce the
>> 'spikes'.  CD's will produce a "stair-step" type of waveform, and the
>> white (pink) noise produces a flat line (or curve), instead of spikes.
>> 

> This is pure, smooth bullshit.  Erase it from your memory and get a
> new roommate.

Sorry, but the roommate is correct.

The process of adding noise to eliminate distortion caused by sampling
is called "dithering."  I am told that it is essential -- if it is
not done, the sampling effects are audible.  It is for that reason
that the highs, especially things like cymbals, sound slightly strange
in many earlier CD recordings (I have trouble hearing that effect myself,
but I know people who can detect it instantly and reliably).