VOCAL Technologies VOCAL Technologies This document describes the RTP payload format for the Mixed Excitation Linear Prediction Enhanced (MELPe) speech coder algorithm developed by Atlanta Signal Processing (ASPI), Texas Instruments (TI), SignalCom (now Microsoft) and Thales Communications with noise preprocessor contributions from AT&T under contract with NSA/DOD as international NATO Standard STANAG 4591. All three different speech encoding rates and sample frames sizes are included. Comfort noise procedures and packet loss concealment are detailed. Also, within the document there are included necessary details for the use of MELP with SDP.