New technology could quadruple phone capacity.

GTE Laboratories said it has devised a way to code and compress four voice channels so that they occupy the space of a single conventional channel without distortion, a development that GTE claimed would also likely reduce transmission costs. Susan Lehto of the Yankee Group, a Boston high-technology consulting firm, said that if the voice quality is as good as the company claims, the device would represent “a significant breakthrough,” reducing line charges.