VFF VoiceFrequencyFilter
计算机英语第230页 ... vfet垂直沟道场效应晶体管 VFFVoiceFrequencyFilter音频滤波器 VFFTVoice–FrequencyFacilityTerminal音频设备终端 ...
tone filter
... tone control 音地制 tone filter 音频滤波器 tone generator 音频发生器 ...
audio bandpass filter ; ABF AudioBandpassFilter ; ABF ; audio band pass filter
Audio Low Pass Filter ; AudioLowPassFilter
Audio High Pass Filter