话音回答
voice answer back
Butlerworth and Ipser’s code
自动回答调制解调器声响耦合器
auto-answer modem acoustic coupler
离散多音调调变
discrete multi-tone modulation
双音调调变频率
dual tone modulation frequency
自动音调调整
ATC
automatic tone correction
AppleTalk回音协定
AppleTalk - echo protocol
拨号备援自动回答装置
dial backup auto answer unit
DBAAU