The Vocoder is a compact module designed to be installed into one of the slots of the Reconfigurable Training Module (RTM). It allows the study of digitized voice transmission in a CDMA environment using reduced data rates, with or without forward error correction (FEC). This module uses two voice encoders to simultaneously encode two audio channels and uses one voice decoder to decode the selected channel. Each voice encoder has a 1/4-inch audio input jack, allowing two microphones (included) to be used as audio sources. The voice decoder has two 2.5 mm audio output jacks for headphones (included), allowing two people to hear the decoded voice signal. BNC connectors are also provided for data and clock outputs and inputs.