A 14 kb/s wideband speech coder with a parametric highband model

This paper describes a new 14 kb/s wideband speech coder. The coder uses a split-band approach, where the input signal, sampled at 16 kHz, is split into two equal frequency bands from 0-4 kHz and 4-8 kHz, each of which is decimated to an 8 kHz sampling rate. The lower band is coded with a high-quality narrowband speech coder, the 11.8 kb/s G.729 Annex E, while the higher band is represented by a simple but effective parametric model. Two new features facilitate efficient coding of the high-band signal: noise modulation and high-frequency reversal. Since the encoding of the lower band is independent of the high-band signal, the narrowband encoder output can be embedded in the overall bitstream. Subjective test results show that this wideband speech coder is capable of producing high quality output speech