Xref: utzoo rec.audio:17134 comp.sys.amiga:45306
Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!rutgers!cbmvax!sterling
From: sterling@cbmvax.UUCP (Rick Sterling - PA)
Newsgroups: rec.audio,comp.sys.amiga
Subject: Re: Removing noise from cassette recording
Keywords: noise removal, DSP
Message-ID: <8884@cbmvax.UUCP>
Date: 8 Dec 89 13:08:08 GMT
References: <116@emdeng.Dayton.NCR.COM>
Reply-To: sterling@cbmvax.UUCP (Rick Sterling - PA)
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 23

In article <116@emdeng.Dayton.NCR.COM> dlundy@emdeng.Dayton.NCR.COM (Dave.Lundy) writes:
> I have been given the task of duplicating a very noisy cassette.
> It was recorded on type I tape with no noise reduction & much too
> low recording level.  Can anyone suggest a reasonable way to make
> a copy with less noise.  I know that there are a number of programs
> for the Amiga that can digitize & edit audio so I thought maybe one
> of them used some kind of DSP techniques that might be useful in this
> case.  Thanks in advance for your suggestions.
> 
> Dave Lundy


Unless you have some highly correlated ``noise'' like 60hz hum, DSP techniques
won't help here. You could ``edit'' out the noise between selections and any
clicks or pops, but thermal and 1/f noise added to the program material can 
usually only be reduced by analogue low pass filtering.

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 Rick Sterling                 Commodore Technology Group       (215)-431-9275
 Test Engineering              UUCP ...{uunet,allegra,rutgers}!cbmvax!sterling

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