Hi

dose any one know the formants vocoder algorithm ?

thanks

Does any of this help? I'm not sure if a phase vocoder is the same thing as a formant vocoder, but googling formant always brings up phase, so here you are!

http://www.panix.com/~jens/pvoc-dolson.par

http://books.google.co.uk/books?id=8yFi1kZD5ucC&pg=PA56&lpg=PA56&dq=formants+vocoder+algorithm&source=bl&ots=DaiBhfNfvM&sig=9jbOVYmlHboOTox5H1VGNVAJGsU&hl=en&ei=wdtAS4TRPJH60wTvpfCRBQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CB4Q6AEwBQ#v=onepage&q=formants%20vocoder%20algorithm&f=false

http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1094078

thank you for your replay
but, no they are not the same

The phase vocoder is similar to the channel vocoder.
However, instead of estimating the pitch, the phase vocoder estimates the phase derivative at the output of each filter.
By coding and transmitting the phase derivative, this vocoder destroys the phase information

whereas

The formant vocoder can be viewed as a type of channel vocoder that estimate the first three or four formants in a segment of speech.
It is this information plus the pitch period that is encoded and transmitted to the receiver.

thank you so much
the second book contains the formant vocoder