def start_audio():
# Initial parameters.
saw = Waveform(saw_wave)
sine = Waveform(sine_wave)
square = Waveform(square_wave)
sine.magnitude = 0.7
saw.magnitude = 0.3
saw.offset = 0.1
square.magnitude = 0.0
square.offset = 0.3
sig_gen = SignalGenerator([sine, saw, square])
audio = Audio(sig_gen, 5)
audio.start_audio()
return audio, sig_gen
