How can I mute a 3.9kHz whistle from a recording? It doesn’t occur when using a different software package (but the same hardware). I’m using Audacity 1.3.3-beta under Ubuntu 7.10, I hope the next stable release will address this issue.
It doesn’t occur when using a different software package (but the same hardware).
What different software package?
I see two possible scenarios. Either the whistling noise is actually present in the file (in which case it would show up using Audacity’s spectrogram and the other piece of software is not playing it for some reason), or Audacity is adding a high frequency whistling noise (in which case I have no idea how you’ve determined the specific frequency).
If you can’t see the whistling noise with Audacity’s spectrogram (it will show up as a horizontal line along the file), then perhaps Audacity is using a different set of audio routines. Audio in GNU/Linux is notoriously confusing. Audacity should be using ALSA drivers if possible (though I have a copy of UbuntuStudio and only the JACK standard will work with Audacity 1.2.6).
If the sound does show up in the spectrogram, then it’s supposed to be present. In that case, you’ll need to use careful EQ to remove it. The Equalizer in Audacity will be able to do this, but it will take some trial and error.
My alternate program is a linux app called SoundRecorder.
I used Aud…1.3.3-beta to analyze the file saved by SR.
The “noise” is NOT present in that file, but ALWAYS present in any file saved by Audacity. When I load the SR file into Aud…, the noise is not present either in the spectrograph or the (audio) playback. My Aud… setup uses ALSA drivers.
To determine the noise frequency, I simply select a “silent” section of the recording, (i.e. with the cartridge off the lp) and use Audacity’s Analyze - Plot Spectrum, and the strongest peak is at 3900Hz.
Another test I did was to try to record at 48K sampling rate. That file is noise free ! When I try to edit that file to save it at 44100Hz sample rate, the file remains “clean” but plays noticeably slower, which does not sound good.
Your suggestions are appreciated. Thanks.
I tried another’s suggestion to install a package called alsa-oss from linux repository, and the results are great, no more whistle in any file from any program at any sample rate. Problem solved. Thanks to all…