Is there a forum.audiohelp somewhere ?

[vmars316]

Hello & Thanks ,
windows 10:
I am looking for a type of noise modification software :
Wanting to vary the volume level of any sound file (.mp3 etc.) ,
at a particular frequency .
The particular frequencies are Brain waves:

Delta wave – (0.1 – 3 Hz)
Theta wave – (4 – 7 Hz)
Alpha wave – (8 – 12.5 Hz)
Mu wave – (7.5 – 12.5 Hz)
Beta wave – (12.5 – 30 Hz)
Gamma wave – (32 – 100 Hz)

So I am wondering if there is a forum.audiohelp somewhere ?
Like videohelp.ccom ?

Thanks

[Cornucopia]

There are a number of good audio-specific forums, but you should still be able to get good answers here.

"Vary the volume level" how?
- Modulation (cyclical/sine, ext. envelope followed) - amplitude, frequency, phase, ring
- Compression/Expansion, Limiting/Unlimiting/Gating

Just so you know, there are plenty of algorithms, processes & devices, as well as engineer's (best practice) habits that would have already diminished, if not eliminated, material that might have existed in those lowest areas that you mention. So you can't operate on something that no longer exists.
You could, of course, generate/synthesize simple tones in those areas, but they wouldn't really be naturally related to the program.

Scott

[JVRaines]

You will need a highly specialized subwoofer and amplifier to produce sound below the frequency of beta waves.

[netmask56]

My system can get down to (just) 18Hz but then I have 5 x 15 Tannoy Gold's and Red's. So some organ works are really great but not much use for chamber music!! I play cello. To get down below 18 ~ 20 Hz really requires 3 or 4 x 18" subs either in an infinite baffle arrangement or a very sturdy cabinet, maybe concrete? A really good system with a very high powered amplifier that can comfortably handle 20Hz it is possible you may start to reproduce sum and difference frequencies ie difference tones below 20Hz but then you start to feel the sound rather than hear it and you do run the risk of personal damage..... https://crab.wordpress.com/2008/01/14/a-short-history-of-sound-weapons-pt2-infrasound/

[jagabo]

Multiply the frequencies by 100 (ie, change the sampling rate), apply a graphic equalizer filter that boots/attenuates the frequency bands, divide frequency by 100.

[tugshank]

those frequencies don't actually exist on the audio file but still perceptible to the brain because of phasing/discrepancies between the left and right channels. i'd stay away from modifying them unless you enjoy epileptic seizures, jk. anyway, cool edit (later on adobe audition) can actually generate these (better than modifying). cool edit even has a theta script which may induce lucid dreaming (ooh).

[pandy]

You will need a highly specialized subwoofer and amplifier to produce sound below the frequency of beta waves.

Not necessarily...

[vmars316]

There are a number of good audio-specific forums, but you should still be able to get good answers here.

"Vary the volume level" how?
- Modulation (cyclical/sine, ext. envelope followed) - amplitude, frequency, phase, ring
- Compression/Expansion, Limiting/Unlimiting/Gating


Scott

"There are a number of good audio-specific forums"
Via google I haven't found one yet .
Anyone know of a specific one ?

I mean to vary the volume level 'down' 'just a bit' and 'back up' at a given frequency .
What 'just a bit ' is , I am not sure yet . Would need to tinker .
Input .mp3 could be anything from Elvis to Bach .

Thanks

[vmars316]

My system can get down to (just) 18Hz but then I have 5 x 15 Tannoy Gold's and Red's. So some organ works are really great but not much use for chamber music!! I play cello. To get down below 18 ~ 20 Hz really requires 3 or 4 x 18" subs either in an infinite baffle arrangement or a very sturdy cabinet, maybe concrete? A really good system with a very high powered amplifier that can comfortably handle 20Hz it is possible you may start to reproduce sum and difference frequencies ie difference tones below 20Hz but then you start to feel the sound rather than hear it and you do run the risk of personal damage..... https://crab.wordpress.com/2008/01/14/a-short-history-of-sound-weapons-pt2-infrasound/

Great link , Thanks

[vmars316]

those frequencies don't actually exist on the audio file but still perceptible to the brain because of phasing/discrepancies between the left and right channels. i'd stay away from modifying them unless you enjoy epileptic seizures, jk. anyway, cool edit (later on adobe audition) can actually generate these (better than modifying). cool edit even has a theta script which may induce lucid dreaming (ooh).

Thanks . I googled for an oldApps version , non that are free , yet .

[pandy]

SoX is free and it should allow you to manipulate some aspects of audio.

http://yumechanmiru.blogspot.nl/2012/02/binaural-beats-generation-using-sox.html

And subwoofer is not required as in brainwaves https://en.wikipedia.org/wiki/Binaural_beats effect is used.

http://discord.sourceforge.net/
https://uazu.net/sbagen/

[jagabo]

Audacity is free and can probably do what you want.

[vmars316]

SoX is free and it should allow you to manipulate some aspects of audio.

http://yumechanmiru.blogspot.nl/2012/02/binaural-beats-generation-using-sox.html

And subwoofer is not required as in brainwaves https://en.wikipedia.org/wiki/Binaural_beats effect is used.

http://discord.sourceforge.net/
https://uazu.net/sbagen/

Wow , Thanks for the links .

I am aware of 'difference tones' , as when I tune my guitar .
The term 'binaural beats' is new to me , very interesting .

[raffriff42]

Wanting to vary the volume level of any sound file ...at a particular frequency...

There's Tremolo (it might require a separate download; try the Nyquist plugin collection)


[Attachment 40414 - Click to enlarge]

If you set starting phase 180° apart for left and right channels, you get a pretty trippy effect.

A related, but different, effect is called binaural beats.
https://www.google.com/search?q=binaural+beats+audacity

[Cornucopia]

Tremolo normally works on the whole sound, so you'd have to do some additional pre- and post- processing EQ to split the sound into band(s) that get operated on (by the tremolo) or those that don't.

Binaural beats are like other sum/difference generated beat frequencies, except they use them among both channels to adjust the disparity between channels (and hence, localization, similar to binaural processes).

Gearslutz is a well-known audio site.
There are a number of sites devoted specifically to various DAW/processors/editors (Logic, ProTools, Cubase, Audacity, etc.)

Keep digging!

Again, even if you generate the tones, unless the intended playback systems are full-bodied, very-high-fidelity setups, you could easily not have your intentions successfully carry through to the audience.

Scott

[vmars316]

raffriff42 :
Great stuff ! I had no idea Audacity can do so much ,
Thanks

[vmars316]

Here's one from Audacity
Binaural-27.5-23.5_4bps.wav
left 27.5 , right 23.5 , yields 4 beats/sec
Thanks