vocoder

from The Free On-line Dictionary of Computing (8 July 2008)

vocoder
vocoding

   <communications> Hardware or software which implements a
   {compression} {algorithm} particular to voice.

   For example {Qualcomm} uses a vocoding algorithm to compresses
   voice data in digital communication systems such as wireless
   {CDMA} and {Eudora} voice attach.

   (1998-04-29)