For HD Voice to work , both phones need to be equipped to capture and transmit the higher-quality sound . HD Voice , which increases voice - calling clarity , is coming to more U.S. networks . Feature expands the range of sound transmitted by phones . AT & T announced its plans to launch HD Voice later this year . T - Mobile , Verizon and Sprint are also looking at the new technology .
HD Voice , which increases voice - calling clarity , is coming to more U.S. networks . Feature expands the range of sound transmitted by phones . AT & T announced its plans to launch HD Voice later this year . T - Mobile , Verizon and Sprint are also looking at the new technology .