Spectral subtraction creates fishtank gurgle noise

[LS2007]

I'm a college student and I record some of my lectures on a high quality DVR (mono 16bit 44K rate). There is a lot of ambient background noise (somewhat like a dull roar sound) which I have been able to clean up most of using WavePad's "Grab noise sample from selected area" and "Apply spectral subtraction based on noise sample" (v3.05). Unfortunately the subtraction process (sample based or automatic) seems to create a very annoying sound left behind that sounds a lot like the gurgling / bubbling of a small fishtank. Any idea what this is and more importantly how to eliminate it? I tried doing a second grab/subtraction pass but no help there.

[critter]

I'm a college student and I record some of my lectures on a high quality DVR (mono 16bit 44K rate). There is a lot of ambient background noise (somewhat like a dull roar sound) which I have been able to clean up most of using WavePad's "Grab noise sample from selected area" and "Apply spectral subtraction based on noise sample" (v3.05). Unfortunately the subtraction process (sample based or automatic) seems to create a very annoying sound left behind that sounds a lot like the gurgling / bubbling of a small fishtank. Any idea what this is and more importantly how to eliminate it? I tried doing a second grab/subtraction pass but no help there.

 

 

I'm having the exact same problem when recording albums and find nowhere on this forum where to fix it. It's either live with the hiss, or be driven insane by the weird noises left behind after the subraction method. I did notice that this post went out in February - I was kind of hoping that someone had a fix by now.

[cutdeep46]

I'm having the exact same problem when recording albums and find nowhere on this forum where to fix it. It's either live with the hiss, or be driven insane by the weird noises left behind after the subraction method. I did notice that this post went out in February - I was kind of hoping that someone had a fix by now.

 

 

It's now aug 21st & I am also waiting for an explaination on this "funky noise" are we grabbing to much sample? I purchased the program & would sure like the keys ty Dale

[Guest nchdc]

Hi, because the background murmur of a lecture theater is a wideband noise source there isn't a neat way to do it. Selecting a period of noise to eliminate using the tools would help if the noise were not a random source (but it is).

Use the remove hum or hiss tool (left side of window) to apply a noise gate. It isn't an ideal application of the tool and it is likely to impact on the lecture you are listening to but is is an effective way of removing wide spectrum noise.

[cutdeep46]

Hi, because the background murmur of a lecture theater is a wideband noise source there isn't a neat way to do it. Selecting a period of noise to eliminate using the tools would help if the noise were not a random source (but it is).

Use the remove hum or hiss tool (left side of window) to apply a noise gate. It isn't an ideal application of the tool and it is likely to impact on the lecture you are listening to but is is an effective way of removing wide spectrum noise.

 

the "fidhtank " gurgling sound may be from taking too large of a sample taking a very small sample seems to get rid of the mishmash sound. it has anyway

things seem to change here & there though ty