PURPOSE: To apply the laser light display device to interesting articles such as interior decorative articles, toys, and audio equipment by drawing a Lissajous' s figure corresponding to the loudness of a sound with laser light.

CONSTITUTION: The laser light display device is provided with a laser unit 14 which emits the laser light and two speakers 12 and 13 which vary the track of the laser light on an X-Y plane by vibration. Further, the device is provided with plural comparators 4 for discriminating between a voltage corresponding to the frequency obtained by waveform shaping through an input means 1 such as a voice input microphone and a previously set voltage value and a central processing unit 5 which determines a vibration frequency with the signals discriminated by the comparators 4. Consequently, when a voice has a frequency within a specific range, the proper Lissajous's figure can be displayed.