Low delay coding of wideband audio (20 Hz-15 kHz) at 64 kbps

Abstract

A 64 kbps coder of wideband (15 kHz) monophonic audio signals is described. Its structure is based on the transform coded excitation scheme, adopted to 7 kHz band signals. Significant modifications are proposed, that yield reduction of delay while keeping an almost transparent quality of speech and music, equivalent to that provided by the MPEG1, layer I1 audio standard at the same bit rate. Algorithmic delay has been reduced to 17 ms -approximately 1/3 the delay of the M PEG coder.