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Re: [ARSCLIST] Heavily distorted signal

DCart has some forensics filters, and just a few days ago I received a
letter informing me that they were sponsoring a forensics audio seminar.

You might find more at www.tracertek.com or www.enhancedaudio.com or

Joe Salerno
Video Works! Is it working for you?
PO Box 273405 - Houston TX 77277-3405
----- Original Message -----
From: "Paul T. Jackson" <trescott@xxxxxxxxx>
To: <ARSCLIST@xxxxxxxxxxxx>
Sent: Thursday, April 17, 2003 12:46 AM
Subject: [ARSCLIST] Heavily distorted signal

> I've lost the original post, but has anyone used audio forensic software?
> Here is one outfit and there is at least one other in Europe:
> http://www.intdevices.com/
> Paul T. Jackson - Trescott Research
> Information Resources and Library Development
> trescott@xxxxxxxxx <mailto:trescott@xxxxxxxxx>
> http://www.bookbay.com/PioneersInBrass.htm
> -----Original Message-----
> From: Association for Recorded Sound Discussion List
> [mailto:ARSCLIST@xxxxxxx]On Behalf Of Mike Richter
> Sent: Wednesday, April 16, 2003 11:50 AM
> Subject:
> Subject:      Re: [ARSCLIST] Heavily distorted signal
> Comments: To: Association for Recorded Sound Discussion List
> <ARSCLIST@xxxxxxx>
> To: ARSCLIST@xxxxxxxxxxxx
> In-Reply-To:  <EB14F3BB8D31184D902B2B6209A1F87207182B35@arion>
> X-Server: High Performance Mail Server - http://surgemail.com
> X-Smite-CRC:
> A#1nGKQX6$1a8yLaQ$n1yIYv#HNsbFH#kZcu02#1yIj62W#1CA6gmw#1hE5y6s$1JS693y
> At 11:36 AM 4/16/2003 -0500, Peoples, Curtis wrote:
> >I have a copy of some Turkish folk poets speaking with and without
> >music. The original analog tape is very distorted. Are there any tricks
> >or techniques to make the voice sound clearer. Is there a certain
> >frequency range I can work with for distortion? Are there any software
> >programs or outboard gear to remedy this problem? Any advice is
> >appreciated.
> For some reason, two replies arrived at my in box before this original
> message.
> You should play with equalization (which may vary from speaker to speaker)
> to optimize retrieval. Frequently in live recording, subsonic and low
> frequencies are excessive and overload the electronics. You cannot correct
> for the recording overload, but you can reduce the playback effects by
> judicious filtering. Experiment for your material; I often use a
> fourth-order filter at about 150 Hz.
> The highs may be loaded with distortion further reducing intelligibility
> but the formants are important. For a male speaking voice, try about a 6
> boost from 1-2 KHz followed by a 3 db per octave rolloff. You may want to
> move it up a half octave for female voices, but again the best
> intelligibility will depend on the faults of the original and the timbre
> the speaker.
> Most denoising (I've not used the Sonic Foundry plugins) will be
> ineffective at low settings and objectionable for artifacts (metallic
> sound, audible echo) when set high enough to be useful. Analogue
> autocorrelation has proved more effective for me than digital, so I
> occasionally pull out an ancient Phase Linear autocorrelator for really
> noisy sources.
> If you have a short sample for me to try digitally, please contact me
> off-list.
> Mike
> mrichter@xxxxxxx
> http://www.mrichter.com/

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