Combined coding of audio and speech signals using LPC and the discrete wavelet transform

The aim of combined coding is to compress a mixed signal consisting of speech and music to the highest possible compression ratio and yet maintain user acceptability. This paper proposes a hybrid coder which is capable of coding combined speech and audio signals sampled over the range 16 kHz to 32 kHz. The coder provides high quality audio coding at competitive bit rates over this range of signal sampling frequencies and offers further coding gains when used with speech signals alone.