Most people do not think about noise pollution as a threat to ecosystems but in fact they can be. If animals cannot hear predators or if it creates an impediment to animal reproduction it will have a cascading effect down to plants if the behavior of herbivores is affected by a noisy environment.
Scientists have discovered that artificial noise levels were twice as loud as natural sounds in 63% of the parks and protected areas in the United States. Furthermore, this noise pollution reduces from 50 to 90% the zones where natural sounds such as birds singing or the sound of a river can be heard.
After all, if artificial noises intrude on our enjoyment of nature it will affect humans as well. The well known benefits of a walk in a park may not be as high and people might even be discouraged from going to such areas.
It seems that the worst noise pollutions come from roads, airplanes and human activities which are industrial in nature. The solution is simple; create shuttle services to some areas in order to discourage people from taking their cars, creating “silence zones” where visitors are encouraged to make less noise. And I suppose that even putting eventually a price tag that is sufficiently high could discourage people in the end.