Can a plane’s sound give away where a video was filmed?

In three steps. The engine’s note never changes; what changes is how often its sound waves reach you.

1. Coming

   Each wave the plane sends starts a little closer to you than the one before, so the waves arrive bunched up. More waves a second sounds like a higher note.

2. Overhead

   For a moment the plane moves neither toward you nor away, and the bunching fades.

3. Going

   Now each wave starts a little further away, so they arrive stretched out, and the note sounds lower.

This is the Doppler effect. For a moving source in still air, the pitch you hear is the source’s pitch × c ÷ (c − v cos θ), where c is the speed of sound, v the plane’s speed and θ the angle between its heading and the line to you when it sent that sound. Take a turboprop on approach at 70 m/s whose propeller hums at 100 Hz, about what a six-blade propeller makes at 1,000 rpm. Coming, you hear about 126 Hz; going, about 83 Hz. Those two ends depend only on the plane’s speed, not on where you stand.

Because of how fast the angle changes. Right under the plane, it swings from “coming” to “going” in a few seconds. Far to the side, the plane is never close, so the angle turns slowly and the same fall from 126 to 83 Hz is stretched out. In the model, half of the drop takes 4.8 seconds right under a plane 300 m up, 17 seconds 1 km to the side and about 25 seconds 1.5 km to the side. At its steepest the pitch falls 5.1 Hz a second right under the plane and only 1.0 Hz a second 1.5 km away.

The rule of thumb: half the drop takes about 1.15 × the closest distance ÷ the plane’s speed. So if you know the speed, the drop gives the distance. And there is a neat bonus. The halfway pitch, about 104 Hz here, arrives at the very moment the plane is closest, even though each sound takes time to reach you. Fitting this curve to estimate an aircraft’s speed and altitude from the ground is an established acoustics technique; B. G. Ferguson described it for propeller aircraft in the Journal of the Acoustical Society of America in 1992.

With public flight tracks. Aircraft with ADS-B broadcast their GPS position, altitude and ground speed once a second, the FAA says. The signals are not encrypted, and networks of hobbyist receivers collect and archive them. Match a drop to the plane that made it, and you know its speed, its altitude and its track.

Then the geometry does the rest. Everyone at the same distance from a straight track hears the same curve, so one flyover puts the listener somewhere on a line either side of it. A second flyover from another direction gives a second pair of lines, and the pairs cross at four spots. The time between the two drops is what picks one.

In early November 2026 the security researcher and YouTuber Colsto showed this at full scale in “I discovered a sound that leaks your exact location (and it’s everywhere)”. He says he located a security-camera clip to within about 100 m from the curves of two flyovers, 920 seconds apart, and the silence of a third flight, matched against about 50 GB of US flight data. He says the work took months and more than 5,000 lines of code, and he is not releasing any software or tools. The 100 m figure is his claim; it has not been independently checked.

That background sound carries information, even when it sounds like silence. Colsto’s clip was a quiet security-camera recording of trees and a riverbank; the planes in it were faint enough to need a spectrogram to see. This is an open-source-intelligence technique, and it works on a recording without its maker knowing.

It is also hard to do. It needs planes loud enough to show up, flights with public tracks, a rough idea of when and where the video was made, and a lot of computing. Colsto himself calls the odds of someone doing this “pretty slim”, TechRadar reports, and he says ordinary noise reduction may not remove the clue. Flyover Doppler Lab explains the physics only: it does not analyse audio, look up flights or locate anyone.

1. 1 See

   Open Flyover Doppler Lab and tap Under the approach path. Pitch: coming → going reads 126 → 83 Hz, Half the drop takes 4.8 s and Closest distance 300 m.

2. 2 Change

   Tap 1 km to the side, or drag the gold pin away from the track. The two ends stay at 126 and 83 Hz, but half the drop now takes 17 s and Steepest drop falls from 5.1 to 1.5 Hz/s. Two blue lines appear, 1 km either side of the track: anyone on them hears this same curve.

3. 3 Understand

   Watch the second flight’s gold lines cross the blue ones at four circled spots. Then tap Cruising jet overhead: 304 → 60 Hz, half the drop takes 37 s, and each sound needs about 29 s just to reach you from 10 km up.

Flyover Doppler Lab flies a straight, level plane at a steady speed through still air, with one engine tone and a listener on flat ground. Real air has wind and temperature layers that bend sound and change its speed: it is about 300 m/s at cruising altitude, not 343. Real planes curve, climb and slow down, buildings and the ground echo, and an engine makes many tones at once. A real search fits the whole curve against many candidate flights and places, with terrain and weather, rather than reading off one number.

The 100 Hz tone is an example; the shape of the drop, and so the distance, does not depend on it. The map is stylized, not a real place, and the plane is sped up so it passes every few seconds. The film opens with a phone video of a jet over a New York street (While on my Journey on YouTube) and uses two short excerpts of Colsto’s video, all credited on screen; the pitch card over the street clip is the model, not that plane’s recording.