Military flights biggest cause of noise pollution on Olympic Peninsula
For years, the Hoh Rain Forest in Washington state's Olympic Peninsula was renowned as one of the quietest places on Earth, its pristine tranquility undisturbed by human sounds amidst its lush, diverse landscape.
Recently, however, the peace has been disrupted. The U.S. Navy transitioned to more powerful aircraft and increased training flights from nearby Whidbey Island, significantly raising levels of noise pollution over what was once among the quietest spots in the continental United States. While local residents and visitors have observed the increase in aircraft noise, there has been no comprehensive analysis quantifying the extent of this disturbance or its impact on people and wildlife.
Now, a study by the University of Washington offers the first detailed assessment of how aircraft noise pollution is affecting the Olympic Peninsula. Published in the journal Northwest Science on November 25, the research reveals that aircraft noise was audible across a substantial area of the peninsula for at least 20% of weekday hours, equivalent to about one hour during a six-hour period. Military planes accounted for approximately 88% of all audible aircraft recorded before the pandemic.
Lead author Lauren Kuehne, formerly with the UW School of Aquatic and Fishery Sciences and now an independent consultant, emphasized the disparity between the Navy's assurances that their aircraft are not significantly louder and claims from local communities experiencing noticeable changes on the ground. The study aimed to provide a realistic measurement of noise that reflects community experiences.
The Navy plans to further increase airborne electronic warfare by 62% and air-to-air combat training by 13% over the Olympic Peninsula, an area of immense historical, cultural, and ecological importance. It is home to eight American Indian tribes, welcomes over 3 million visitors annually to Olympic National Park (a UNESCO World Heritage Site), and supports numerous species, some of which are threatened or endangered under the federal Endangered Species Act.
“The Olympic Peninsula is not only a critical wildlife habitat but also a cultural and recreational hub,” explained co-author Julian Olden, a professor at the UW School of Aquatic and Fishery Sciences.
During the study, researchers monitored soundscapes at three primary sites from June 2017 to May 2018, strategically located at Third Beach and Hoh Watershed near the coast, and inland on the Hoh River Trail. They deployed recorders to capture continuous audio for 10-day periods and enlisted volunteers to assist in analyzing nearly 3,000 hours of recorded data.
“The accessibility of this data allows people to hear and see for themselves—it’s not overly technical,” noted Kuehne. “I wanted people to feel empowered to engage with the analysis.”
Their findings documented nearly 5,800 flight events across all sites and periods monitored, with military aircraft comprising the majority at 88%, followed by propeller planes (6%), commercial airplanes (5%), and helicopters (less than 1%). Most military aircraft noise occurred on weekdays between 9 a.m. and 5 p.m., primarily from Growlers—Boeing EA-18G jets used for electronic warfare exercises resembling “hide and seek” maneuvers with targets.
The study concluded that the aircraft noise, predominantly intermittent and reaching sound levels typically between 45 and 60 decibels—comparable to urban air traffic in Seattle—occasionally spiked above 80 decibels, akin to persistent noise levels under Seattle's former waterfront viaduct.