Adobe Audition and removing static from signals

[Pr0ph3t]

Hi everyone,

Hope this is the right place to ask this, I have some static filled signals recorded in mono (should I do stereo from on will it make it easier ?)

I'm trying to remove the static to hear the low voice better is there a way to do this ? I tried acapella setting for center channel removal but no good too low. Anybody tried this before ? Thanks !

 

[WB9YBM]

I doubt doing it in stereo will make much difference; I'm assuming there's probably some kind of program out there somewhere that'd help, or maybe filtering it through some Dolby system...

 

[Whiskey3JMC]

Audition and Audacity (open source) both have static and noise removal functions. They help to a degree but don't expect crystal clear results. A simple Google search will bring up numerous demo videos

 

[Pr0ph3t]

Audition and Audacity (open source) both have static and noise removal functions. They help to a degree but don't expect crystal clear results. A simple Google search will bring up numerous demo videos

Yeah but hard to find for this specific purpose. Was playing around with the different noise removal. I guess the way I should of phrased my question is the following:

Am I aiming to remove high frequencies or low frequencies ? Either sounds crappy tbh

Anyway it's cool I'm going to continue experimenting eventually I'll make a profile and share it I'm sure someone will have something to add

Thanks

 

[polkaroo]

I don't know what the range of analog radio audio is, but assuming something like an old telephone it would be 250-4kHz or so. So grab a sample of just noise to put into the noise reduction filter. Exit out, notch out or high and low-pass the audio (There's no point in filtering out the frequency range that doesn't contain speech audio), then play around with the noise reduction filter. That's the easy part. I have no idea if you can do it with Audition without plugins, but next step could be to look at the entire spectrum in a 3D space and start replacing the static. It's the equivalent of pixel-level airbrushing and retouching in Photoshop.

 

[WB9YBM]

I don't know what the range of analog radio audio is,

approx 300Hz - 3 KHz, give or take depending on what a radio manufacturers' engineering teams' decisions. Slight pre-emphasis in Motorola radios below 300Hz out of consideration for passing sub-audible signaling tones ("PL"). (Don't know if other mfr are doing that--I only worked on Motorola audio processing during my time in their R & D labs.)

 

[DC31]

Hi everyone,

Hope this is the right place to ask this, I have some static filled signals recorded in mono (should I do stereo from on will it make it easier ?)

I'm trying to remove the static to hear the low voice better is there a way to do this ? I tried acapella setting for center channel removal but no good too low. Anybody tried this before ? Thanks !

Take a recorded sample and open it with Audacity. Then plot the soectrum:


I think that then you will find the frequencies that you want to filter out. The above plot shows why under 300 hz and over 2500 hz are commonly filtered out. The low frequencies are usually a hum and the upper ones are the hiss.

 

[Pr0ph3t]

Take a recorded sample and open it with Audacity. Then plot the soectrum:

View attachment 97955
I think that then you will find the frequencies that you want to filter out. The above plot shows why under 300 hz and over 2500 hz are commonly filtered out. The low frequencies are usually a hum and the upper ones are the hiss.

Ah thank you that explains it nicely !

 

[paulears]

There are much, much better audio applications that can do this. I’ve just added spectral layers to my audio studio, after trying the cut down version within Cubase. It can remove a huge range of issues using noise prints and artificial intelligence. your problem is that noise prints don’t work because the hiss in the background is random in nature, so unlike pink or white noise, removal doesn’t work. You are left, as people have said, with filtering to remove noise that contains no wanted information. What is left is simple poor signal to noise ratio, and that is a snag. You could try frequency specific. Expansion to look at the vowel and consonant transients and boost just them, but you need specialist software, because the old rule that still holds true without clever software, is that if it’s not recorded, it cannot be amplified. I have audition and it can manage hissy preamps or guitar amps but not radio background noise.

 

[Pr0ph3t]

There are much, much better audio applications that can do this. I’ve just added spectral layers to my audio studio, after trying the cut down version within Cubase. It can remove a huge range of issues using noise prints and artificial intelligence. your problem is that noise prints don’t work because the hiss in the background is random in nature, so unlike pink or white noise, removal doesn’t work. You are left, as people have said, with filtering to remove noise that contains no wanted information. What is left is simple poor signal to noise ratio, and that is a snag. You could try frequency specific. Expansion to look at the vowel and consonant transients and boost just them, but you need specialist software, because the old rule that still holds true without clever software, is that if it’s not recorded, it cannot be amplified. I have audition and it can manage hissy preamps or guitar amps but not radio background noise.

I did notice the noiseprints don't do much but the more I play with it the more I realize that there's 2 components as obvious as it is, how you record and what the environment you're recording in is like. Turns out having my low humming fan a few feet away might be imperceptible to my ear but changes a lot when it comes to recording. Keep in mind until my aux cable comes in (I got the 2.5/3.5->3.5 cable that's apparently intended for this purpose so should be good) I'm using my headset wrapped around the uv82 with the mouthpiece transmitting into the mic of the headset. So I mean I'm expecting miracles here. Still though, trudging through the noob stuff I'm learning valuable lessons.

This radio stuff's pretty cool finally. It started off as a way of disaster recovery communications type thing (and airsoft, got sick of not knowing how to use my radio properly) but I fell in love with the scene.

 

[paulears]

Hang on? You're using a microphone???? That's a terrible way to do it! Headphone outlet to recording device line in - that will clean it up far better than any system of using a mic. The speaker is band limited and weedy, the microphone is band limited and thin and weedy too - no wonder you can't clean it up - it's compromised in so many ways. a simple cable will help no end and remove all the compromises you have. I thought you were listening to distant noisy signals just peeping above the noisefloor - not attaching a mic to the radio with sticky tape!

 

[Pr0ph3t]

Hang on? You're using a microphone???? That's a terrible way to do it! Headphone outlet to recording device line in - that will clean it up far better than any system of using a mic. The speaker is band limited and weedy, the microphone is band limited and thin and weedy too - no wonder you can't clean it up - it's compromised in so many ways. a simple cable will help no end and remove all the compromises you have. I thought you were listening to distant noisy signals just peeping above the noisefloor - not attaching a mic to the radio with sticky tape!

Yah I got one on the way don't worry, it's just coming from the moon apparently so it's around Feb 10th I ordered it about a week ago. So meanwhile was making due lol Honestly it's not that bad I've gotten fairly decent at cleaning.

Now I have hackrf one, just got it worked on kali. I have NO idea what I'm doing. I'm listening to an FM station as I was doing the tutorial... I really hope there's more to it than this and unlocking electric cars