Voice Changing/Cloaking Codec possible?


#1

Would it be possible to alter the g711 codec so that it would change to voice of an incoming caller. What I have in mind something to would protect the callers identity?

Thanks for your thoughts.

Tom


#2

This may be what you are looking for:

voip-info.org/wiki/view/Aste … ch+Changer


#3

if you want to play funny pranks on your friends, then pitch changing is fine. I’m not sure how the voice changer library attached to the above link works, so it may or may not be what you need.

However if you seriously need to protect your identity, simply pitch changing isn’t enough. Someone can easily record the conversation, and increase the pitch again to get a result similar to your own voice. To effectively cloak, you need to randomly modulate frequency/pitch/speed independently and unpredictably. The result sounds very voice disguised, but is extremely difficult to piece back into the original sound. I’d even dump most of the voice data (maybe with lpc10 codec) first before you apply that filter, so even if they do manage to piece it back together all they get is the mr. roboto voice.

That said, this is all theoretical. But then again, if you are doing something where you seriously need to protect yourself, asking a forum isn’t the best way to start :smile:


#4

[quote=“IronHelix”]if you want to play funny pranks on your friends, then pitch changing is fine. I’m not sure how the voice changer library attached to the above link works, so it may or may not be what you need.

However if you seriously need to protect your identity, simply pitch changing isn’t enough. Someone can easily record the conversation, and increase the pitch again to get a result similar to your own voice. To effectively cloak, you need to randomly modulate frequency/pitch/speed independently and unpredictably. The result sounds very voice disguised, but is extremely difficult to piece back into the original sound. I’d even dump most of the voice data (maybe with lpc10 codec) first before you apply that filter, so even if they do manage to piece it back together all they get is the mr. roboto voice.

That said, this is all theoretical. But then again, if you are doing something where you seriously need to protect yourself, asking a forum isn’t the best way to start :smile:[/quote]

You are right, I am not aware of any software that may be readily integrated with Asterisk to provide true disguising of voices.


#5

Thanks for your thoughts gentlemen. Some further explanation may be required. I’m trying to develop a system where the callers hear their voices as altered while speaking in real time, thereby giving them some measure of confidence that they will remain anonymous. I’m aware that simply altering the pitch of the voice does not offer the highest degree of identity protection as it could easily be altered back to the callers original pitch-- but it’s a start. Can you lower the pitch to make even a female voice sound like a very deep male voice?