The decibel is the classification level of the size of the sound. When the decibel exceeds a range value, it is considered noise. If the sound exceeds a range value for a long time, it is considered noise pollution. It is generally believed that the sound of one decibel can be just The sound that can be heard, and the sound below 15 decibels is a sound that will feel very quiet, but when the sound reaches 30 decibels, it is considered to be the volume of a whisper. If it exceeds 50 decibels, it will affect rest and sleep.