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From: phd@speech1.cs.cmu.edu (Paul Dietz)
Newsgroups: rec.audio,sci.electronics
Subject: Re: Restoration
Keywords: loudspeaker, speaker, bibliography
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Date: 14 Jul 88 10:11:03 GMT
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In article <4944@husc6.harvard.edu> gallaghe@husc8.UUCP (Paul Gallagher) writes:
>Here's a question maybe someone out there can answer:
>Why isn't it possible to completely restore a recording: for example, to remove
>all extraneous noise (hiss, clicks, coughs), even to make a reasonable guess
>about information not in the original recording (for example, given a score
>and a knowledge of the harmonics of a voice or an instrument, to recreate
>something close to the sound of the original performance)?

Actually, this sort of thing is commonly done. I remember hearing a story
about some Caruso recordings that were restored by having a singer
imitate as closely as possible the original, and then using this to
generate optimal filters that were then applied to the original recordings.

I suggest you look at the literature on adaptive filtering. Widrow and
Stearns "Adaptive Signal Processing" in the Prentice-Hall Signal
Processing Series is a good place to start.

Paul H. Dietz                                        ____          ____
Dept. of Electrical and Computer Engineering        / oo \        <_<\\\
Carnegie Mellon University                        /|  \/  |\        \\ \\
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"If God had meant for penguins to fly,             -->--<--        / / |\\\  /
he would have given them wings."            _________^__^_________/ / / \\\\-