Audacity - Noise Reduction ??
Posted: Mon Nov 11, 2019 9:56 pm
Author: hunter [ Mon Mar 07, 2016 7:29 pm ]
Post subject: Audacity - Noise Reduction ??
For you Audacity Guru's
When doing noise reduction with a file on Audacity
Under Step 2
What settings do you use for:
Noise Reduction (db):
Sensitivity:
Frequency Smoothing Bands:
Whatever I am doing...
Its making an owl sound like its call is reverberating (with its head) inside of a tin bucket
(and sounds absolutely horrible and just barely like an owl
Author: Rebelistic [ Tue Mar 08, 2016 4:37 am ]
Post subject: Re: Audacity - Noise Reduction ??
The more filters you use takes away from the vocals and distorts sounds. The more you play with it the better you can get to understand when to use them. If I can't improve a by running a high filter and low filter, in my opinion it is too contaminated to use. It is VERY tough to pull distant audio from closer contamination like bugs etc.
Author: therealsuperdave [ Tue Mar 08, 2016 5:32 am ]
Post subject: Re: Audacity - Noise Reduction ??
I rarely apply noise reduction. That is comparable to tampering with potential evidence and compromises your recording where it would be inadmissible as evidence.
But if you want to modify an audio recording for your own enjoyment, then try using the defaults, which were noise reduction = 30, sensitivity = 0, frequency smoothing = 150, and attack/decay time = 0.15.
Each recording may have different noises to remove so there would not be one standard setting to always use.
You need to understand what each item does to the recording, and set the numbers to your liking, changing them on every recording. To understand what each slider does, read the Audacity manual, which I copied and pasted below.
Use trial and error with each slider, and listen to the preview. Also listen to a sample of the noise being removed to be sure a part of the desired sound is not in the part being removed.
(My recommendation is to not do any noise removal.) but if you insist, here is the Audacity manual's explanation of how Audacity removes components of the sounds:
---------------(copied and pasted from the manual--------------------------------
Noise Reduction (dB): Controls the amount of volume reduction to be applied to the identified noise. Use the lowest value that reduces the noise to an acceptable level. Higher values than necessary may make the noise even quieter, but will result in damage to the audio that remains.
Sensitivity: Controls how much of the audio will be considered as noise, on a scale of 0 (off) to 24 (maximum). Greater sensitivity means that more noise will be removed, possibly at the expense of removing some of the desired signal as well. Lower values may result in the appearance of artifacts in the noise-reduced audio. Set this control to the lowest value that achieves effective noise removal without the introduction of artifacts.
Frequency Smoothing (bands): At values of 1 or higher, this control spreads the noise reduction into the specified number of neighboring bands. This modifies the signal you were intending to keep, but if artifacts remain in the noise-reduced audio the smoothing can make those artifacts sound more acceptable. There is a chance that smoothing will make the desired audio less clear, so where your desired signal is strong and of wide frequency range and the noise is light, try leaving this control at 0 (off).
If you hear artifacts in the noise-reduced audio after setting Sensitivity as high as possible without eliminating desired audio, try setting Frequency Smoothing to a value between 1 and 6 bands. The width (in Hertz) of a frequency band is dependent on the sampling frequency of the track. Width = sampling frequency / 2048 = 21.53 Hz at 44100 Hz sampling rate.
Time smoothing is always applied by Noise Reduction (attack of 20 milliseconds and release of 100 milliseconds) but the settings are not configurable. Any frequency smoothing you request is applied after time smoothing.
The default setting is setting is 3, settings lower than this tend to favor music and higher settings tend to favor spoken word.
Reduce: Select this option to filter out the noise from the selection.
Residue: Select this option to hear the sound that would be filtered out if you chose "Reduce". This is useful for finding the optimum settings that do not damage the audio. If you can hear recognizable bits of the desired sound in the residue, it is likely that you have set Noise Reduction too high or Sensitivity too high.
Author: hunter [ Tue Mar 08, 2016 7:51 am ]
Post subject: Re: Audacity - Noise Reduction ??
Thanks guy's !!!!
Author: YankeeSearch [ Tue Mar 15, 2016 5:57 pm ]
Post subject: Re: Audacity - Noise Reduction ??
When I play with noise reduction, I actually use Windows Media Player... it does not make it permanent, but sometimes it helps to isolate noises better than Audacity... It also helps me BEFORE I go into audacity to get a better sense of the band where the noise I want to eliminate is.
Author: Holotype [ Sat Jun 04, 2016 11:55 pm ]
Post subject: Re: Audacity - Noise Reduction ??
Just find that fundamental frequencies of the noise . If it's in that frequencies of the program leve it alone . Or use a shelving eq and lower it a couple db. I would say you could notch out frequencies below 100 Hz, and above 10 kHz . A high pass , low pass filter is great for this . Should help with background noise. Judicious use of a compresser can bring the call in question more forward. You could also use a noise gate on the call. In the studio I don't use noise reduction plugins seems to cause too much phase shift . And the cookie cutter curves are not specific enough for all program material
Author: Holotype [ Sun Jun 05, 2016 12:08 am ]
Post subject: Re: Audacity - Noise Reduction ??
Just find you a cheep graphic eq with as many frequencies as you can Alexis made some really cheap ones 1rack space. And go to town with your fingers ,in stead of mousing around . A whole lot easier and faster.use your ears guys . A spectrograph is great if you can read it ,and an audio engineer . But if not just use your ears .all the computer stuff can be misleading .
Post subject: Audacity - Noise Reduction ??
For you Audacity Guru's
When doing noise reduction with a file on Audacity
Under Step 2
What settings do you use for:
Noise Reduction (db):
Sensitivity:
Frequency Smoothing Bands:
Whatever I am doing...
Its making an owl sound like its call is reverberating (with its head) inside of a tin bucket
(and sounds absolutely horrible and just barely like an owl
Author: Rebelistic [ Tue Mar 08, 2016 4:37 am ]
Post subject: Re: Audacity - Noise Reduction ??
The more filters you use takes away from the vocals and distorts sounds. The more you play with it the better you can get to understand when to use them. If I can't improve a by running a high filter and low filter, in my opinion it is too contaminated to use. It is VERY tough to pull distant audio from closer contamination like bugs etc.
Author: therealsuperdave [ Tue Mar 08, 2016 5:32 am ]
Post subject: Re: Audacity - Noise Reduction ??
I rarely apply noise reduction. That is comparable to tampering with potential evidence and compromises your recording where it would be inadmissible as evidence.
But if you want to modify an audio recording for your own enjoyment, then try using the defaults, which were noise reduction = 30, sensitivity = 0, frequency smoothing = 150, and attack/decay time = 0.15.
Each recording may have different noises to remove so there would not be one standard setting to always use.
You need to understand what each item does to the recording, and set the numbers to your liking, changing them on every recording. To understand what each slider does, read the Audacity manual, which I copied and pasted below.
Use trial and error with each slider, and listen to the preview. Also listen to a sample of the noise being removed to be sure a part of the desired sound is not in the part being removed.
(My recommendation is to not do any noise removal.) but if you insist, here is the Audacity manual's explanation of how Audacity removes components of the sounds:
---------------(copied and pasted from the manual--------------------------------
Noise Reduction (dB): Controls the amount of volume reduction to be applied to the identified noise. Use the lowest value that reduces the noise to an acceptable level. Higher values than necessary may make the noise even quieter, but will result in damage to the audio that remains.
Sensitivity: Controls how much of the audio will be considered as noise, on a scale of 0 (off) to 24 (maximum). Greater sensitivity means that more noise will be removed, possibly at the expense of removing some of the desired signal as well. Lower values may result in the appearance of artifacts in the noise-reduced audio. Set this control to the lowest value that achieves effective noise removal without the introduction of artifacts.
Frequency Smoothing (bands): At values of 1 or higher, this control spreads the noise reduction into the specified number of neighboring bands. This modifies the signal you were intending to keep, but if artifacts remain in the noise-reduced audio the smoothing can make those artifacts sound more acceptable. There is a chance that smoothing will make the desired audio less clear, so where your desired signal is strong and of wide frequency range and the noise is light, try leaving this control at 0 (off).
If you hear artifacts in the noise-reduced audio after setting Sensitivity as high as possible without eliminating desired audio, try setting Frequency Smoothing to a value between 1 and 6 bands. The width (in Hertz) of a frequency band is dependent on the sampling frequency of the track. Width = sampling frequency / 2048 = 21.53 Hz at 44100 Hz sampling rate.
Time smoothing is always applied by Noise Reduction (attack of 20 milliseconds and release of 100 milliseconds) but the settings are not configurable. Any frequency smoothing you request is applied after time smoothing.
The default setting is setting is 3, settings lower than this tend to favor music and higher settings tend to favor spoken word.
Reduce: Select this option to filter out the noise from the selection.
Residue: Select this option to hear the sound that would be filtered out if you chose "Reduce". This is useful for finding the optimum settings that do not damage the audio. If you can hear recognizable bits of the desired sound in the residue, it is likely that you have set Noise Reduction too high or Sensitivity too high.
Author: hunter [ Tue Mar 08, 2016 7:51 am ]
Post subject: Re: Audacity - Noise Reduction ??
Thanks guy's !!!!
Author: YankeeSearch [ Tue Mar 15, 2016 5:57 pm ]
Post subject: Re: Audacity - Noise Reduction ??
When I play with noise reduction, I actually use Windows Media Player... it does not make it permanent, but sometimes it helps to isolate noises better than Audacity... It also helps me BEFORE I go into audacity to get a better sense of the band where the noise I want to eliminate is.
Author: Holotype [ Sat Jun 04, 2016 11:55 pm ]
Post subject: Re: Audacity - Noise Reduction ??
Just find that fundamental frequencies of the noise . If it's in that frequencies of the program leve it alone . Or use a shelving eq and lower it a couple db. I would say you could notch out frequencies below 100 Hz, and above 10 kHz . A high pass , low pass filter is great for this . Should help with background noise. Judicious use of a compresser can bring the call in question more forward. You could also use a noise gate on the call. In the studio I don't use noise reduction plugins seems to cause too much phase shift . And the cookie cutter curves are not specific enough for all program material
Author: Holotype [ Sun Jun 05, 2016 12:08 am ]
Post subject: Re: Audacity - Noise Reduction ??
Just find you a cheep graphic eq with as many frequencies as you can Alexis made some really cheap ones 1rack space. And go to town with your fingers ,in stead of mousing around . A whole lot easier and faster.use your ears guys . A spectrograph is great if you can read it ,and an audio engineer . But if not just use your ears .all the computer stuff can be misleading .