Image Number 2 for United States Patent #5506578.
An apparatus to facilitate volume control for route aural guidance. When supplying a guidance voice to a loudspeaker 34a, a voice control section 30 disconnects the loudspeaker 34a from audio and outputs the guidance voice through the loudspeaker. A volume control screen is displayed on a display section 28 where the user adjusts the volume by touching the screen. When the voice control section 30 switches a signal to the loudspeaker 34a, a mute circuit 40a is operated to mute the voice output before the voice is output through the loudspeaker 34a. When the user terminates volume adjustment, the voice control section 30 outputs a voice for volume confirmation or check at the adjusted volume through the loudspeaker 34a. The user can check the adjusted volume at this time.