Looking for help removing static from interview recording

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mrconnolly127
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Joined: Mon Nov 27, 2017 10:27 pm
Operating System: OS X 10.11 El Capitan or later (macOS)

Looking for help removing static from interview recording

Post by mrconnolly127 » Tue Nov 28, 2017 2:23 am

Hello:

I am a university researcher who is an advanced Mac user (OS 10.13.1) but a novice at using Audacity (v. 2.2.0).

I am looking for guidance in fixing an interview recording that is plagued with static/crackling throughout. About six weeks ago I conducted an interview with a single research subject over a landline telephone. It was recorded using an Olympus digital recorder WS-600S (output format: MP3) that was directly attached to the telephone via a Hello Direct Virtuoso Headset Phone Amplifier (see https://www.terapeak.com/worth/hello-di ... 040520032/ ). We didn't know there was a problem with this set-up until our transcribers returned half a dozen audio files with complaints about crackling/buzzing every time the level meter maxed out. I've attached a 15-second sample (WAV format).
WS600148_clip5.wav
15-sec clip of crackly interview recording
(1.69 MiB) Downloaded 18 times
I am hoping that a proficient Audacity user can suggest an effect or fix to apply to my recordings that will make them a lot less difficult for transcribers to listen to. Will gladly provide any additional information upon request. To anyone who can help, many thanks in advance!

kozikowski
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Re: Looking for help removing static from interview recordin

Post by kozikowski » Tue Nov 28, 2017 2:43 am

I can help a little by shearing off all the stab-you-in-the-ear-with-an-ice-pick tones.

The test clip is your work for the first ten and my patch for the remainder.

Let us know if that's enough. Once you overload or "clip" the work, the recorder stops following the show and starts making up garbage on its own. In brief, there is no clear show back there to filter to. There is no goal.

Koz
Attachments
WS600148_clip5Patched.wav
(1.69 MiB) Downloaded 25 times

kozikowski
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Posts: 40453
Joined: Thu Aug 02, 2007 5:57 pm
Operating System: OS X 10.9 Mavericks
Location: Los Angeles

Re: Looking for help removing static from interview recordin

Post by kozikowski » Tue Nov 28, 2017 2:48 am

Select the whole show by clicking in the lower-right of the track INFO panel.

Effect > Amplify > New peak: -2dB.

Effect > Low Pass Filter: 4000Hz, 36dB.

Koz

kozikowski
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Posts: 40453
Joined: Thu Aug 02, 2007 5:57 pm
Operating System: OS X 10.9 Mavericks
Location: Los Angeles

Re: Looking for help removing static from interview recordin

Post by kozikowski » Tue Nov 28, 2017 3:10 am

Recording a phone conversation is not for the easily frightened. Did you try to connect this adapter into the MIC-IN of a laptop computer? That's where the distortion came from. The volume from the adapter would be very seriously too loud for that connection.

You can try to reduce the volume by some manner (there's not a lot of information available), or adapt it to an actual high-volume device such as the Behringer UCA-202.

That's it between my laptop and my high-volume analog sound mixer.

Image

On a wild guess, something such as this.
Screen Shot 2017-11-27 at 19.05.03.png
Screen Shot 2017-11-27 at 19.05.03.png (182.97 KiB) Viewed 293 times
Or this and a straight stereo RCA cable.
http://www.musiciansfriend.com/accessor ... e&index=27

Image

Koz

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