Which ITU standard defines 8-bit audio compression used in standard telephony and low-end videoconferencing?

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Multiple Choice

Which ITU standard defines 8-bit audio compression used in standard telephony and low-end videoconferencing?

The audio standard being asked about is G.711, which defines 8-bit PCM audio used in standard telephony. It samples audio at 8 kHz and encodes each sample as 8 bits, giving a fixed 64 kbps stream. The compression is achieved with regional companding—μ-law in North America/J Japan and A-law in Europe—followed by linear 8-bit encoding. This approach is favored for basic telephony and low-end videoconferencing because it is extremely simple, introduces minimal latency, and offers broad interoperability across traditional phone networks. G.722, while also an ITU-T codec, is a wideband option that provides higher fidelity and uses more bandwidth, so it isn’t the standard for 8-bit mono telephony. H.239 is about adding a second video stream in videoconferencing, not audio compression. Gateway is a device type, not an audio codec.

The audio standard being asked about is G.711, which defines 8-bit PCM audio used in standard telephony. It samples audio at 8 kHz and encodes each sample as 8 bits, giving a fixed 64 kbps stream. The compression is achieved with regional companding—μ-law in North America/J Japan and A-law in Europe—followed by linear 8-bit encoding. This approach is favored for basic telephony and low-end videoconferencing because it is extremely simple, introduces minimal latency, and offers broad interoperability across traditional phone networks.

G.722, while also an ITU-T codec, is a wideband option that provides higher fidelity and uses more bandwidth, so it isn’t the standard for 8-bit mono telephony. H.239 is about adding a second video stream in videoconferencing, not audio compression. Gateway is a device type, not an audio codec.

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