Voice distortion software

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Voice distortion software

Post by Baldo »

I'm doing an interview with someone who needs to disguise their voice for legal reasons.

Any software apps that I can use for this purpose?

Many thanks
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Re: Voice distortion software

Post by Wonks »

I'd have thought any pitch changing software with formant changing should do the job. Most DAWs have one as standard or something like Soundtoy's Little Alter Boy.

Adjust the pitch and formant setting and it will sound very different.
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Re: Voice distortion software

Post by Baldo »

thanks for that. I assume that there is no way to reverse engineer the distorted voice. To prevent this I suppose we need some kind of random noise added so that it would be impossible to reverse engineer.

Am I right?
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Re: Voice distortion software

Post by Wonks »

Possibly.

Then there's the option of copying the vocal to say three tracks, doing a different amount of pitch and formant change to each one and recombining them. So it then wouldn't be easy to reverse engineer as any other pitch or formant change correctly applied for one voice part would still leave 2/3 of the voice very different sounding.

You could give it a go on your own voice and see what you think.

I'd be more concerned that anyone who knew the speaker would recognise any vocal mannerisms they had, any turns of speech they often used etc. Umms and ahhs.

I'd suggest the interview be scripted so you could change anything that might give them away or mentioning something unplanned.
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Re: Voice distortion software

Post by N i g e l »

It might be easier just to have the interview transcription voiced by an actor or text to speech synthesizer.
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Re: Voice distortion software

Post by Wonks »

That would probably be safest.
Here's a simplistic article but it does bring up a few other points of how voices can be recognised. https://kids.frontiersin.org/articles/1 ... 022.702664

There are AI programs that will analyse the way the words are spoken. If there is a small pool of possible people who could have made the interview and there are recordings of the possible interviewees voices that could be used as reference data, then you might easily pick the correct one by elimination of the others.

If it's a simple disagreement like a staff member at a school disagreeing with the headmaster's policies, then mangling the voice is probably fine. But a witness in a major crime case where there's a lot at stake, then I wouldn't use their voice at all.
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Re: Voice distortion software

Post by Wonks »

And unless it's pertinent to the interview subject, then you could leave out all gender references. If there are 20 possible people who could have made the interview and only two of them are female and you tell them you are interviewing Mrs X, then it probably won't take much for whoever the interview affects to work out which of the two women it is.
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Re: Voice distortion software

Post by tea for two »

Preehaps a Toy Megaphone voice changer approx €10.
https://m.youtube.com/watch?v=tQIiyIx-isc
at 27seconds.
I thunk this would be harder to reverse engineer than software.
Baldo wrote: Sun Mar 26, 2023 1:36 pm no way to reverse engineer the distorted voice. To prevent this

Preehaps also feel comfortable for the person knowing hearing they are disguising distorting their voice using something they can hold as this Toy Megaphone, instead of software.
Baldo wrote: Sun Mar 26, 2023 1:05 pm I'm doing an interview with someone who needs to disguise their voice for legal reasons.

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Re: Voice distortion software

Post by Wonks »

The interview needs to be intelligible!
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Re: Voice distortion software

Post by Folderol »

Wonks wrote: Sun Mar 26, 2023 3:35 pm The interview needs to be intelligible!

Hmmm. Is that a new, novel idea?
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Re: Voice distortion software

Post by Wonks »

Call me radical, but I think it's worth a go!
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Re: Voice distortion software

Post by tea for two »

Wonks wrote: Sun Mar 26, 2023 3:35 pm The interview needs to be intelligible!

Lol ! There is that.
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Re: Voice distortion software

Post by Kwackman »

N i g e l wrote: Sun Mar 26, 2023 2:14 pm It might be easier just to have the interview transcription voiced by an actor

This is the safest method, and used by broadcasters.
Voice distortion by whatever method usually sounds strange and distracting to listeners, and pitch shift won't disguise voice characteristics.
Someone else's voice avoids you being sued!
If it's for a video usually it's considered good practice to caption with "Actor's voice". If it's for audio only, there's normally a "his/her words are spoken by an actor" type of sentence before the interview is played.
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