digital call quality

The term digital call quality had entered into popular English language in the late 20th century at a time of increasing popularity of GSM mobile (cell) phones ('2G') replacing the preceding analogue system. The popular meaning of the phrase is taken to suggest GSM audio performance is comparable to that of digital audio (such as Philips Audio Compact Disc) . However, the difference here is the GSM system has been optimised to use only the minimum bandwidth required to make the caller's voice recogniseable to the callee, and to recreate most of the sounds that spoken words use, sufficiently for spoken sentences to be understandable.
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