Before revision: Adaptive Differential Pulse Code Modulation (ADPCM), former ITU-T G.721, 32 kbit/s used in STE secure telephone Modern vocoders that are used in communication equipment and in voice storage devices today are based on the following algorithms: Algebraic code-excited linear prediction (ACELP 4.7–24 kbit/s) Mixed-excitation linear prediction (MELPe 2400, 1200 and 600 bit/s) Multi-band excitation (AMBE 2000 bit/s – 9600 bit/s) Sinusoidal-Pulsed Representation (SPR 600 bit/s – 4800 bit/s) Robust Advanced Low-complexity Waveform Interpolation (RALCWI 2050, 2400 and 2750 bit/s) Tri-Wave Excited Linear Prediction (TWELP 600 –9600 bit/s) Noise Robust Vocoder (NRV 300 and 800 bit/s) Vocoders are also currently used in psychophysics, linguistics, computational neuroscience and cochlear implant research.
After revision: Adaptive Differential Pulse Code Modulation (ADPCM), former ITU-T G.721, 32 kbit/s used in STE secure telephone Modern vocoders that are used in communication equipment and in voice storage devices today are based on the following algorithms: Algebraic code-excited linear prediction (ACELP 4.7–24 kbit/s) Mixed-excitation linear prediction (MELPe 2400, 1200 and 300 bit/s) Multi-band excitation (AMBE 2000 bit/s – 9600 bit/s) Sinusoidal-Pulsed Representation (SPR 600 bit/s – 4800 bit/s) Robust Advanced Low-complexity Waveform Interpolation (RALCWI 2050, 2400 and 2750 bit/s) Tri-Wave Excited Linear Prediction (TWELP 600 –9600 bit/s) Noise Robust Vocoder (NRV 300 and 800 bit/s) Vocoders are also currently used in psychophysics, linguistics, computational neuroscience and cochlear implant research.