A voice processing apparatus modulates an input voice into an output voice according to a parameter set. In the voice processing apparatus, a microphone inputs an audio signal which represents an input voice having a frequency spectrum specific to the input voice. An audio signal processor is configured by a parameter set to process the audio signal according to the parameter set to modify the frequency spectrum of the input voice. A parameter table is provided for storing a plurality of parameter sets, each of which differently characterizes modification of the frequency spectrum by the audio signal processor. A CPU selects a desired one of the parameter sets from the parameter table, and configures the audio signal processor by the selected parameter set. A loudspeaker outputs the audio signal which is processed by the audio signal processor and which represents an output voice characterized by the selected parameter set.