As long as it does not exceed 70 decibels, it is fine. If it exceeds 70 decibels, it is noise, and it will also cause damage to your ears. It was mentioned in our study of sound, light and electricity in physics. The vibration of butterfly wings is below 20 Hz, which is inaudible to humans. The vibration frequency of flies is too high, so we think it is very noisy. And frequencies above 20,000 Hz are inaudible to humans, called ultrasonic waves such as dolphins and bats. , below 20 Hz are infrasound waves. Sound is produced by vibration.