According to NASA, background noise impacts the way people react to the buzzing and whirring of electric air taxis—but not in the way you might think.
The space agency this month released the initial findings from its Varied Advanced Air Mobility Noise and Geographic Area Response Difference, or VANGARD, study. The research’s most notable conclusion is that people living in areas with high background noise (think urban centers such as New York City) tend to report more annoyance with the air taxis than those living in low-noise areas.
“We wanted to know if people in low or high background noise zones would be more annoyed by the air taxi sounds, and to what extent, even without their usual background sounds present during the test,” said Sidd Krishnamurthy, lead researcher at NASA’s Langley Research Center in Virginia.
NASA said the results of the study could guide the designs of advanced air mobility (AAM) aircraft manufacturers. American electric vertical takeoff and landing (eVTOL) air taxi companies Joby Aviation, Archer Aviation, Beta Technologies, and Wisk Aero all claim their designs will be substantially quieter than helicopters—in Archer’s case, 100 times quieter.
“Studies have suggested that aircraft noise can be a source of community annoyance, disrupt sleep, adversely affect academic performance of children, and could increase the risk for cardiovascular disease,” reads a 2024 Government Accountability Office report on the FAA’s legal authority to regulate aircraft noise.
The space agency does not have the power to create policy based on the study. But it could share its findings with the FAA, which is tasked with setting aircraft noise certification standards and gauging environmental impacts from noise. Part 36, for instance, contains noise standards for tiltrotor aircraft with swiveling propellers—a common feature of electric air taxis.
“With air taxis coming soon, we need to understand how people will react to a variety of future aircraft sounds,” said Krishnamurthy. “This test filled a critical gap, and its results will improve how we predict human reactions to noise, guiding the design and operation of future aircraft.”
Do Air Taxis Have a Noise Problem?
NASA’s Urban Air Mobility Noise Working Group recommended the VANGARD study back in 2020 as a way to augment the sparse data on human noise responses to AAM aircraft.
The study comprised nearly 360 people living in or near Los Angeles, New York City, and Dallas-Fort Worth—locations the aforementioned eVTOL air taxi firms are targeting for commercial operations.
Participants listened to 67 individual aircraft flyover sounds that simulated the operations of six different aircraft, including departures, approaches, and cruise. The vehicles included NASA-owned designs as well as industry concepts.
Participants were told to find a quiet environment and were prompted, without knowing which aircraft they were hearing: “Imagine hearing this sound several times each day while outdoors and near your home. How annoying would this sound be to you?”
They rated their level of annoyance with each sound on a scale of 1 to 10. Participants also provided their ZIP codes so that researchers could sort them into low and high background noise areas.
People living in noisier areas reported, on average, higher annoyance scores with the air taxi sounds. Researchers hypothesized that those people may simply be more sensitive to extra noise.
A follow-on noise sensitivity test is expected to shed more light on the results, which will be expanded upon in a larger report in the coming months. However, the study is not intended to be comprehensive—it does not gauge, for example, how air taxi sounds could be masked by high background noise.
Next Steps
Though NASA collected the noise response data, regulators such as the FAA could get the most out of it.
For example, the agency can create special conditions for AAM aircraft that do not fit the Part 36 noise standards for tiltrotors. The NASA survey could help it determine which designs may require those provisions.
The FAA could also create air traffic arrival or departure procedures to route air taxi flights over areas that are sparsely populated or less sensitive to noise. Per the 2024 GAO report, “modifications to existing routes or creation of new routes establishing where AAM aircraft fly” could require it to conduct a National Environmental Policy Act (NEPA) review, including an assessment of noise impacts.
Tribal, state, and local governments have the authority to develop and enforce zoning regulations—which would determine where vertiports could be built—among other measures. New York City law, for instance, requires all helicopter takeoffs and landings to be over water “to prevent unnecessary noise.” The city in April barred nonessential helicopter flights that do not meet the FAA’s strictest noise standards.
Airport operators, meanwhile, can have the FAA review Part 150 Noise Compatibility Programs that would allow them to mitigate noise at their respective airports.
The VANGARD research was led by NASA’s Revolutionary Vertical Lift Technology (RVLT) project, part of the agency’s broader research into AAM. Agency researchers are working with scientists, universities, and air taxi manufacturers themselves to study everything from noise and passenger comfort to traffic management and crash safety.