audio book
audio disk
audio engineering
audio frequency
audio (frequency) device
audio (frequency) effect
audio frequency transformer
audio-frequency wave
audio generator
audio head
audio indicator
audio-lingual
audio modulation
audio operator
audio oscillator
audio output
audio reproduction
audio response device
audio response unit
audio signal
audio tape
audio transformer
audio transmission
audio typist
audio-visual
audio-visual equipment
audio-visual method
audio-visual recorder
audiofrequency
audiofrequency meter