  This paper focuses on a newly developed transparent nADPCMB MLT speech coding
algorithm. Our coder first decomposes the narrowband speech signal in subbands,
a non linear ADPCM scheme is then performed in each subband. The signal subband
decomposition is piloted by the equivalent Modulated Lapped Transform (MLT)
filter bank. The novelty of this algorithm is the non linear approach, based on
neural networks, to subband prediction coding. We have evaluated the
performance of the nADPCMB MLT coding algorithm with a session of formal
listening based on the five grade impairment scale standardized within ITU - T
Recommendation P.800.
