There are many lighting display circuits excited by music signals, which can be seen in dance halls, discos and some audio equipment. Amateur production can be made by LED because it requires little power. There is a kind of bar display, and the effect is also good. You can use 1 LEDs or 1-bit LED light-emitting bars, and the number of lights varies with the volume. It is necessary to use 5V power supply (which can be taken from the internal power supply of the speaker or regulated by 785) and LM3914 (linear display) or LM3915 (exponential display-in line with human auditory characteristics) LED level indicating circuit. Related circuits can be found on Baidu.