The ITU-T Recommendation for adaptive differential pulse code modulation (ADPCM) voice coding and compression of high-fidelity 7 kHz voice at 64/56/48 kbps. See also ADPCM.
An ITU standard for speech codecs that uses the ADPCM method and provides high-quality audio at 64 Kbps. Introduced in 1988, G.722 is a wideband codec that transmits voice in the 50-7000 Hz frequency range. G.722 uses the same ADPCM method as G.721 but uses 16 kHz samples rather than 8 kHz to support the wider frequency range. See G. standards, ADPCM and wideband audio.