As per NASA, ambient sounds influence how individuals respond to the hum and whir of electric air taxis—but not in the manner you would expect.
This month, the space agency published the early results from its Varied Advanced Air Mobility Noise and Geographic Area Response Difference, or VANGARD, study. The study’s key finding is that individuals residing in regions with significant ambient noise (such as bustling cities like New York City) are more likely to express irritation with air taxis compared to those in quieter areas.
“We were curious about whether individuals in areas with low or high levels of ambient noise would experience more irritation from air taxi sounds, and to what degree, even when their typical background noises were not present during the test,” said Sidd Krishnamurthy, lead researcher at NASA’s Langley Research Center in Virginia.
NASA mentioned that the findings of the research might influence the development of advanced air mobility (AAM) aircraft by manufacturers. American electric vertical takeoff and landing (eVTOL) air taxi companies such as Joby Aviation, Archer Aviation, Beta Technologies, and Wisk Aero all assert that their designs will be significantly quieter than helicopters.Archer’s case, 100 times quieter.
“Research indicates that aircraft noise may cause community irritation, interfere with sleep, negatively impact children’s academic performance, and potentially raise the risk of heart disease,” states a 2024 Government Accountability Office report.reporton the FAA’s legal power to oversee aircraft noise.
The space agency lacks the authority to develop policies based on the research. However, it can share its results with the FAA, which is responsible for establishing aircraft noise certification standards and assessing environmental effects from noise. For example, Part 36 outlines noise regulations for tiltrotor aircraft that have rotating propellers—a typical characteristic of electric air taxis.
Air taxis are on the horizon, and we must comprehend how individuals will respond to different sounds from future aircraft,” stated Krishnamurthy. “This test addressed a significant gap, and the findings will enhance our ability to forecast human reactions to noise, influencing the design and operation of upcoming aircraft.
Is There a Sound Issue with Air Taxis?
In 2020, NASA’s Urban Air Mobility Noise Working Group suggested the VANGARD study as a method to enhance the limited information regarding human reactions to noise from AAM aircraft.
The research involved almost 360 individuals residing in or around Los Angeles, New York City, and Dallas-Fort Worth—areas where the mentioned eVTOL air taxi companies plan to launch their commercial services.
Participants heard 67 distinct aircraft flyover sounds that represented the operations of six various aircraft, including takeoffs, landings, and cruising. The aircraft included NASA-developed designs as well as industry proposals.
Participants were instructed to locate a quiet area and were asked, without being aware of the specific aircraft they were listening to: “Picture yourself hearing this noise multiple times every day while outside and close to your residence. How bothersome would this sound be to you?”
They assigned a level of irritation for each sound using a scale from 1 to 10. Participants also shared their ZIP codes so that researchers could categorize them into regions with low and high levels of ambient noise.
Individuals residing in noisier neighborhoods generally recorded higher levels of irritation due to the sounds from air taxis. Scientists proposed that these individuals might be more susceptible to additional noise.
A subsequent noise sensitivity test is anticipated to provide further insight into the findings, which will be detailed in a more extensive report over the next few months. Nevertheless, the study is not designed to be all-encompassing—it does not, for instance, assess how air taxi noises might be concealed by significant background noise.
Next Steps
Even though NASA gathered the noise response data, agencies like the FAA could derive the greatest benefit from it.
For instance, the agency may establish specific requirements for AAM aircraft that do not meet the Part 36 noise regulations applicable to tiltrotors. The NASA survey might assist in identifying which designs could necessitate such exceptions.
The FAA might also establish air traffic arrival or departure procedures to direct air taxi flights over regions with low population density or reduced noise sensitivity. According to the 2024 GAO report, “changes to current routes or the development of new routes specifying where AAM aircraft operate” may necessitate a National Environmental Policy Act (NEPA) review, which includes evaluating noise effects.
Indigenous, state, and local governments are empowered to create and implement zoning rules—deciding the locations of vertiports—along with other policies.New York City law, for example, mandates that all helicopter takeoffs and landings occur over water “to avoid unnecessary noise.” The city in Aprilbarred nonessential helicopter flightsthose that fail to comply with the FAA’s most stringent noise regulations.
Airport administrators, on the other hand, can have the FAA examine Part 150 Noise Compatibility Programs that enable them to reduce noise at their specific airports.
The VANGARD study was conducted under the leadership of NASA’s Revolutionary Vertical Lift Technology (RVLT) initiative, which is part of the agency’sbroader researchto AAM. Agency researchers are collaborating with scientists, universities, and air taxi companiesmanufacturers themselvesto examine all aspects ranging from noise and passenger comfort totraffic management and crash safety.
