Strange Sounds When using Noise Reduction

[tyshu]

Hello,

I've been trying out the "free" version of WavePad. I've tried using the Noise Reduction feature on a video soundtrack (isolated as a .wav file) but no matter what I do, although the hum is reduced, a "flanger" type sound is introduced into the file. It's there during silent intervals as well as making voices sound as if they were run through a flanger sound effect filter. I've tried the different methods for noise reduction (auto, multi-band, using a 6 second hum-only sample) but nothing seems to help. Is anyone familiar with this problem and does anyone know of any solutions? I would really appreciate any help.

 

Ty

[Guest MichaelJee]

Hi,

 

PM sent requesting file transfer over FTP so we take a look a look in the lab.

 

Cheers

M

[tyshu]

Hi,

 

PM sent requesting file transfer over FTP so we take a look a look in the lab.

 

Cheers

M

 

Hi,

Thanks Michael, I replied to your PM and I sent you "before and after" 26 second long snippets of the file by ftp (at least I think they got sent).

 

Regards,

Ty

[haelen]

Hello,

I've been trying out the "free" version of WavePad. I've tried using the Noise Reduction feature on a video soundtrack (isolated as a .wav file) but no matter what I do, although the hum is reduced, a "flanger" type sound is introduced into the file. It's there during silent intervals as well as making voices sound as if they were run through a flanger sound effect filter. I've tried the different methods for noise reduction (auto, multi-band, using a 6 second hum-only sample) but nothing seems to help. Is anyone familiar with this problem and does anyone know of any solutions? I would really appreciate any help.

 

Ty

 

I'm trying to resolve this too Ty. I suspect it comes from have to "aggressive" amount of noise reduction applied.

 

Cheers,

Tim

[PeaceMaker]

http://nch.invisionzone.com/index.php?showtopic=11421

[haelen]

http://nch.invisionzone.com/index.php?showtopic=11421

 

Thanks for this. I found an old email from someone who uses WavePad for voiceovers. She gave me a "formula" for noise reduction part of which included using the "gated" NR. I set this to -50 dB . It was just speech and seemed to work fine.

 

Best,

tim

[tyshu]

I'm trying to resolve this too Ty. I suspect it comes from have to "aggressive" amount of noise reduction applied.

 

Cheers,

Tim

 

Thanks, Tim. I had also noticed that doing a little noise reduction at a time seemed to decrease the flanger effect some, but it doesn't seem to be a practical method if you're working with a large file (like a movie soundtrack) because of the time it would take to keep doing small amounts of noise reduction over and over. Maybe it would help with small files.

 

Regards,

 

Ty

[tyshu]

http://nch.invisionzone.com/index.php?showtopic=11421

 

Much apprediated. . .thanks for the info.

 

Regards,

 

Ty

[tyshu]

Hey Michael,

 

I tried to PM you, but I don't think it went through, so I'll respond here.

 

I was able to duplicate your results. Some of the detail was lost, so I tried lowering the decibel value in the Noise Gate option of the Noise Reduction filter (I went as low as -14db) and that restored much of the detail (along with some hiss/hum). I think if I play around with the db value I just might get an acceptable result. At least there's no flanger sound! :-)

 

Thanks, mate, for your efforts on this, they're certainly appreciated.

 

regards,

 

Ty

 

Hey Ty,

 

 

 

Used gated set to -2dB, and then normalised 100%. Seems to have removed a lot of the static at the start. I cant really tell if its removed too much detail though.

 

 

 

Have a listen and let me know.

 

 

 

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Regards

 

 

 

Michael G

 

Technical Support

 

NCH Software

 

Canberra Australia

 

 

 

www.nchsoftware.com <http://www.nchsoftware.com>

 

 

 

 

 

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