I think this has been asked to initiate a discussion. So i shall rather attempt to answer this complex question and see what happens!!.

There is no one single answer to this. Many solutions have been worked out. According to me , Challenge has always been in implementation of these solutions. Certain establishments and governments have been more successful than the other.

1. Industrial noise- Its effect on hearing health has definite solution, in terms of ear protective devices that are monitored by regular audiometry

2. Recreational Noise- awareness among users as to their health hazard and regulations by civic authorities. www.dangerousdecibel.com offers some perspective on these.

3. Personal listening device- turn the volume down!! WHO initiative.

4. Traffic noise- well maintained engines, shift to electric vehicles.