Audio signal coding method - codes audio signals with low bit rate and delay to provide low quality signal and with high bit rate and delay to provide high quality signal.

Abstract
The coding method has a lower quality coded signal provided by coding the audio signals with a relatively low bit rate and low delay time and a higher quality coded signal provided by coding the audio signals with a relatively high bit rate and delay time, with either signal selectively transmitted to a decoder. Pref. the lower quality signal is decoded and the audio signal is delayed by the delay resulting from coding at the lower bit rate and the decoding time, to allow the signals to be compared, the obtained difference coded at the higher bit for transmission to the decoder after transmission of the lower quality coded signal. USE - For scalable audio coding.