1. INTRODUCTION
Waveform Interpolation (WI) is a method for coding narrowband speech with high perceptual quality at low bit rates [1]. It is based on the description of speech (in practice the LP residual) as a surface formed from evolving pitch-length Characteristic Waveforms (CWs). To date, most research into WI has focused on narrowband (300 Hz to 3.4 kHz bandwidth) speech [1]. The work described in this paper focuses on WI applied to wideband (50 Hz to 7 kHz bandwidth) speech [2]. The motivation is for a low bit rate (below 6 kbps) solution to wideband speech coding.