Could you please help me reverse the volume?

I don’t mean flipping the waveform vertically (like “Invert”), I mean literally making the loudest sound quietest, and no sound maximum volume. I wrote “1 / (track)” in the Nyquist Prompt, but it did nothing. I tried changing it a little, but still didn’t work. Could you point out how to reverse the volume, if possible, while preserving vocals and/or keeping it HQ?

In other programs, I’ve tried flipping each half of the wave by making sawtooth-shaped wave in bipolar or inverted in unipolar, using a compress effect with high and low inverted, inverting an audio spectrum loudness, inverting Gain and preserve Frequency, and all that, but if that isn’t possible, is it at least possible to make a code with the methods I tried, in a combo box with names for the methods?

no sound maximum volume.

The “No Sound” part will depend on the bit depth. So it’s open ended. Also, similar to existing compressors and expanders, you have to choose the rate of the applied correction. It’s not one thing.

I can’t imagine what that would sound like. Why are we doing this?


This plug-in does something like that: Envelope follower / ducker
though I’ve no idea how silence can become “maximum volume”. What does that even mean? You want to replace silence with some kind of noise or some other sound? :confused:

If the vocals are mixed in with other sounds, it’s probably not possible to separate them out (in high quality) without very expensive, purpose made software, (such as “Melodyne studio” ~ $700) and a lot of time tweaking it.

The (free) “KONTRAST” plugin can boost quiet sounds and attenuate loud sounds at the same time …

before-after KONTRAST.png
OK for electronic music, but not much else because of the digital-artefacts generated.
(Possibly useful to make faint background clicks & hum conspicuous, so they can be removed).

Trebor, I ran into a problem. I can’t set the max below min, or min above max. Both KONTRAST and LEVELS do this. I can’t change it, because it is a .DLL file and not a .NY file. How to set low and high backward in KONTRAST and LEVELS?

“invert spectrogram” is the brief you’ve specified.

Trebor, It’s neat, but when I applied the effect twice, it didn’t revert to normal… just have to ask; Why did that happen if double negative is positive? Is it very lossy? Is there a way around this? Did you use a different scale of dB or Hz of some sort? Did you invert differently than I did?

When I inverted the spectrum in a different program, where there was no sound was white noise, and frequencies were replaced in noisy any-other frequency.

The picture shows what I mean by “inverted spectrum”, putting it in negative.

The KONTRAST plugin is only capable of an approximation of inverting spectrogram.
(In a true negative the darkest parts would become the brightest, and vice versa).
but it’s close enough to let you hear what an inverted (negative) spectrogram sounds like.

Inevitably inverting a spectrogram will be a lossy process: the signal-to-noise ratio is going to get worse with repeated applications, (and you will accumulate digital artefacts).

I use the logarithmic (rather than linear) spectrogram …

If you’re looking for a filter which brings out faint voices which don’t actually exist you’re on a futile quest.

Would something like this work? Left is low-frequency, right is high-frequency, top is loud, bottom is soft. With a Nyquist plug-in, If I vertically flipped this around like so, Would it still be lossy? And Could I write it in Nyquist somehow?

That depends what you mean by “work”.

Run this code in the Nyquist Prompt:

;version 4
(mult  10 (hp *track* 20000))

I did have the idea I could reverse the playback and volume, so it sounds like it is still playing forward with backward notes. When you reverse the playback, the sound that faded out at the end fades in at the end. Similarly, reversing the volume would reverse the fade, but without reversing the notes. Just thought that would be useful in that way, so you don’t hear weird, reversed sound while playing in reverse.

How about that? Would something like this be possible in a plugin, or code? (But disincluding reversing playback, I want to reverse the volume in a way that SOUNDS like it is played backward, or rewinding.)

Can reverse the audio in chunks each less than a second long,
see this plugin … Reverso

Possibly reverse-reverb: i.e. reverse, apply reverb, reverse again (so is back the right way around), play.

(Squaring-the-circle is not possible).

Well, it is cool. If you combine Reverso with Reverse, you can make a Reverse/Rewind CD like effect… CDs jump back instead of smoothly playing backward. With both being an reverse effect, it was double-negatived to a positive, but reversed like a CD.

That is an interesting effect… When you hold the previous button, it sounded like it was skipping, and Reverso combined with Reverse gives a similar effect, except reverses at normal speed.

But, the effect I am looking for needs to reverse the direction while preserving instruments, and/or the other way, at least somewhat. When you reverse a sound fading out, it fades in. When you invert volume, something similar could happen. Combining the two should sound like the instrumental still sound normal/forward, but notes are played reversed.

If anyone finds my message on Reverso, I put it there by accident, I meant to put it here.

To play notes in reverse order, but not have them sound backwards, you need MIDI …

Audacity only has limited support for MIDI … Missing features - Audacity Support

Hello, steve, this

;version 4
(mult  10 (hp *track* 20000))

didn’t work. The first picture is unchanged, the second is with the code, the third is reversed Volume/dB. I want to reverse the sound in dB where the first one looks like the third. Yes, change the entire audio, not just the analysis or that part.

Looking at this:

it clearly did work.
It may not have done what you wanted it to do, but it does what it was designed to do.

How did you make that third sound?

It is done with an Image editor, but it is showing what I want to try to do. If the FFT was a line, it would appear flipped upside down. If it was a black-and-white spectrum, the brightness may appear in negative… Am I missing something?

What do you expect that would sound like?

Notice that in the original image, there is no sound at all above about 14,000 Hz. What is the inverse of “none”?

In other programs, when you invert silence in an entire frequency spectrum (like brightness is volume for each frequency), you hear white noise… which sounds like static.

If the lower half the sound (say 1 - 11025 Hz) is white noise, and the entire thing is inverted, the lower is silent and the upper frequency (11025 - 22050 Hz) is audible (though it was silent before).

That is what I expect it to do…

Is there a volume effect plugin for this, perhaps?

Yeah, it probably would be impossible to be infinity (1/0), but you could reverse the range (0% - 100%) and 0 dB would be the opposite of silence, -∞ (negative-infinity) dB. I’m not sure if the symbol will go through, so if you see a square, it is supposed to be the infinity symbol.