This　paper　presents　the　quantization　schemes　for　the　magnitude　spectra　of　the　slowly　evolving　waveform　(SEW)　and　rapidly　evolving　waveform　(REW)　components　in　a　2　kb/s　waveform　interpolation　(WI)　coder.　The　SEW　magnitude　spectrum　is　quantized　using　a　DCT-based　predictive　vector　quantization　approach.　The　REW　magnitude　spectrum　is　quantized　using　a　matrix　quantizer　based　on　the　combined　dimension　conversion　method.　The　objective　measures　and　subjective　results　indicate　that　the　proposed　quantization　schemes　are　effective　in　achieving　good　quantization　accuracy.　©2004　IEEE.