Found It!
It took me 4ever, but found the artikel. IT was publiced in september 1991 and it was called Stemverschuiver.
The project uses a sound chip which was specialy designed for this.
MSM6322 ( sms)
If you search the internet for this chip..you'll find a lot of schematics and stuff.
It's a chip that only needs a few extra components.
HAve fun
Not sure if it will help or hinder but...
Intel makes a "Sound Morpher" which will change anyones voice or other sound.
Unfortunately it only runs on a PC and not realtime...but maybe it will help you see what can be done...and the price is very reasonable..I got one free when I ordered their QX3+ PC based Microscope...it even includes a digital recorder which you dump back into the pc.
Thanks Emdee, it looks promising... by the way you have any idea where can i buy this chip? In the Europe or if you have an adress (I have send e-mail to oki official dealer in Germany but no reply...)
I have no idea where to get the chip. It's been so many years sinds it was published, It could be absolete by now.
However, if it is absolete there's proberly a replacement. Check the manufactorers website.
Maybe you can find the chip here:
h**p://www.a-source.nl/uk/index-uk.htm
Don't now if they sell in low quantity.
Good luck