Washington University and Columbia University researchers found that urban public transport arising from the noise level that may lead to hearing impairment, and this damage is permanent. It is estimated that currently about 30 million people around the world by noise damage hearing.

scientists surveying the public transport system in New York noise level found in the transport, the MTR of 80.4 db, 79.4 db light also; station is even more noisy, and up to 102.1 db subway platforms, bus stations up to 101.6 db. The overall situation is: the vehicle is higher than the car, the major stations higher than the station, the underground above the ground.

Columbia University, Dr Nagel said: In the noisy site, two minutes a day spent waiting passengers is sufficient to cause the hearing loss.奈泽Washington University, said: Long-term exposure to environmental noise will be abated damage caused by chronic, but as long as the increase in noise levels, damage to a significant increase in risk, for example, 95 dB 85 dB risk is 10 times, 75 dB 100 times, "you as long as the decline in hearing sensitivity 10 dB, you heard other people's ability to speak would be a big fight discount 。\"

United States Environmental Protection Agency and the World Health Organization recommended: daily 24-hour average noise level should be below 70 decibels, the general would not affect the hearing. Nagel-hung said that in addition to hearing damage, excessive noise with high blood pressure, heart disease, endocrine disorders, sleep disorders, and even can affect the learning ability of children.

Therefore, the scientists recommended the strengthening of personal protection. Listening to music on headphones will not only fail to reduce the noise, but will also increase, because people to increase the volume of MP3 to pressure than the surrounding noise.防噪a variety of ear plugs, ear protectors can be effectively reduced the noise levels fall within the scope of security, it is recommended to wear out when坐公�