voice-grade channel的意思|示意

话音级信道 ... voice-frequency 话音频率 voice-grade channel 话音级信道 voice-grade line 音频（通信）线路 ...

话音级通道 ... voice-frequency facility terminal(VFFT) 音频设施终端机 voice-grade channel 话音级通道 voice-grade lines 话音级线路 ...

音频频道 ... voice control 声控 voice-grade channel 音频频道 voice keying 语音键控 ...

音频道 ... 视平线 visual horizon 音频道 voice-grade channel 声音操作装置 voice-operated device ...