Abstract
With the era of progress and development, the level display has spread to our lives, work, various aspects of scientific research, has become a more common products appear in our vision of. This paper presents a summary of the audio-level display, it has 10 light-emitting diode display visual voice of loudness. When the loudness of sound, light-emitting diode light on the number of multi-When the loudness of the voices of hours, LED lit on the number of less. The design of the 10 CD4017 chip output to control 10 of the LED lit and extinguished, the VCO frequency audio input levels reflect the size and use VCO as CD4017 the pulse of the external clock input, and Self-generated pulse oscillator clock input to control the on-off and reset the counter. The display can be used for entertainment occasions measured applause, shouting relative loudness of sound, can also be used for home audio systems, for the system, such as audio level meter.
