According to the regulations of the Occupational Safety and Health Administration (OSHA), the human ear can bear the maximum sound intensity of 85 decibels for 8 hours without negative effects. These laws and regulations have influenced the design of industrial headphones. However, in consumer products, there is no hard and fast regulation of the maximum sound intensity.

So what is the maximum volume of most MP3 players circulating in China market? Generally, the maximum volume of MP3 is around110dB.

Sound below 40 decibels has no effect on human body; When the sound is between 40 decibels and 60 decibels, the nervous system will be affected if the human body is in this environment for a long time. At this time, for every 3 decibels increase in noise, the noise energy will double; When the sound reaches 65 decibels to 80 decibels, the cardiovascular damage of people is more than 20% higher than that of people living in a noise environment of 50 decibels. When the noise exceeds 80 decibels, it will do great harm to people's hearing. When the noise exceeds 100 decibel, it is unbearable noise. The sound reaches 120 decibels, which is equivalent to a Boeing 747 flying over, and human health will be greatly damaged in a short time.