This fall National Park Service officials are expected to ask all park superintendents to come up with plans for limiting noise in national parks and protecting the “soundscape,” or the natural sounds unique to each area. “All of a sudden, places that look the same as 100 to 200 years ago don’t sound like they did,” said Wes Henry of the NPS, who is leading a federal effort to restore quiet to parks. Helicopters, airplanes, off-road vehicles, snowmobiles, and car alarms can all destroy the peace and tranquility that many park visitors seek. Over the past year, the NPS has restricted or banned snowmobiles and personal watercraft like Jetskis in some parks and national seashores, in part because of the noise they make and in part because they pollute and disturb wildlife.