Abstract: An audio coding system encodes and decodes audio signals as a plurality of independent layers of coded audio data. A basic representation of the original audio signal may be reconstructed from decoding of a single layer of coded audio data. However, a more complete representation of the original audio signal is reconstructed by decoding additional layers of coded audio data. The coding system finds application with decoding systems of varying processing power, and in transmission systems having communication channels that are characterized by intermittent transmission errors and/or variable capacity. At an encoding system, an audio signal is broken into a plurality of frequency bands which are filtered, down sampled and independently coded. A decoding system inverts the coding process applied at the encoding system for whatever number of layers that is determined will be decoded.