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.

[deleted]

Hi,

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

Cheers

tyshu

MichaelJee wrote:

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,

haelen

Tyrone Shulace wrote:

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

PeaceMaker wrote:

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

haelen wrote:

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,

tyshu

PeaceMaker wrote:

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

Much apprediated. . .thanks for the info.

Regards,

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,

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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