Within Size Errors
Does Silence Mean A UFO Was Huge?
Silence can make an object seem stranger, but it does not prove that a light or shape is enormous or far away.
On this page
- Why sound is a poor distance ruler
- Small quiet objects versus distant aircraft
- How silence should be handled in reports
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Introduction
A common feature in UFO reports is the statement that an object was completely silent. Witnesses may reason that if something appeared large, moved through the sky, and produced no audible noise, it must have been extraordinarily distant, technologically advanced, or physically enormous. In practice, silence is a much weaker clue than it first appears.
For reports involving unidentified flying objects (IFOs), missing sound often contributes to mistakes about distance and size. People naturally expect large aircraft to be noisy and nearby objects to be audible. However, sound propagation outdoors is complicated, many aerial objects are inherently quiet, and atmospheric conditions can suppress or redirect noise. As a result, a silent object may be small and nearby, while a noisy aircraft can sometimes appear surprisingly quiet from the ground. Silence can make a sighting seem stranger, but by itself it does not establish an object’s size, altitude, or nature. [eaglepubs.erau.edu]eaglepubs.erau.eduAeroacoustics of Flight Vehicles –noise propagation by refracting and sometimes focusing sound over longer distances.Read more…
Does Silence Mean a UFO Was Huge?
The short answer is no.
In many witness accounts, size estimates depend on an assumed distance. If an observer believes a silent light must be far away, they may place it at aircraft altitude. Once that assumption is made, the object’s apparent angular size can translate into an enormous physical size. If the distance assumption is wrong, the size estimate collapses with it.
This is the same basic problem identified in analyses of UAP and UFO reports that involve forced perspective. AARO has noted that observers frequently lack reliable depth cues and may unintentionally assign incorrect distances to aerial objects. When distance is uncertain, estimates of both size and speed become unreliable. [AARO]aaro.milParallax effects cause the object to be.Read moreAAROEffect of Forced Perspective and Parallax View on UAP…As the airborne observer moves from position 1 to 2 to 3 in the air, they vi…
Silence often acts as an extra layer of confidence rather than genuine evidence. A witness may think:
- It made no sound.
- Therefore it could not be nearby.
- Therefore it must have been far away.
- Therefore it must have been huge.
Each step depends on assumptions that may not be justified.
Why Sound Is a Poor Distance Ruler
Humans are generally good at using sound in familiar environments, but the open sky creates unusual conditions.
Aircraft noise does not travel in a simple, predictable way. Atmospheric temperature gradients, humidity, wind, terrain, buildings, and ground effects can all alter how sound reaches an observer. Under some conditions, sound is refracted upward or away from listeners, creating areas where an aircraft may be visible but surprisingly difficult to hear. Under other conditions, sound can travel farther than expected. [eaglepubs.erau.edu]eaglepubs.erau.eduAeroacoustics of Flight Vehicles –noise propagation by refracting and sometimes focusing sound over longer distances.Read more… [NASA]ntrs.nasa.govGeometric Acoustics for Aircraft Noise Scattering (20220509NASA Technical Reports ServerGeometric Acoustics for Aircraft Noise Scatteringby Y Guo · 2022 · Cited by 17 — This paper discusses aircra…
There is also a timing issue. A distant aircraft may be seen before its sound arrives. If the observer watches only briefly, the object can appear silent even though noise would have become audible later.
Research into aircraft sound perception shows that people’s judgments of aircraft height and size are influenced by a combination of visual and acoustic cues, not by sound alone. Perceived size and perceived altitude can diverge from reality, especially when observers have limited reference points. [Frontiers]frontiersin.orgFrontiers Soundscape Assessment of Aircraft Height and SizeFrontiersSoundscape Assessment of Aircraft Height and SizeDecember 18, 2018 — by G Memoli · 2018 · Cited by 9 — We propose a method to as…
In practical terms, the absence of sound rarely provides a precise measure of range.
Ambient Noise Masks More Than People Realise
Many UFO sightings occur in environments that are not acoustically quiet.
Road traffic, wind, insects, waves, industrial activity, air-conditioning systems, crowds, and urban background noise can conceal faint aircraft sounds. Research on unmanned aircraft systems has found that noticeability depends heavily on the surrounding acoustic environment, not just on the sound produced by the aircraft itself. [PMC]pmc.ncbi.nlm.nih.govEffect size estimation plots…
A witness may genuinely experience a sky object as silent even when it is producing noise that simply fails to stand out from the background.
Small Quiet Objects Versus Distant Aircraft
One reason silence is a risky clue is that very different objects can produce the same impression.
A distant jet, a high-altitude balloon, a satellite, a drone, a glider, or a lighter-than-air object may all appear as silent lights or shapes under the right conditions. Some are quiet because they are extremely far away. Others are quiet because they generate little sound in the first place.
This creates a classic identification trap. A witness sees a silent object and unconsciously chooses the wrong category.
For example:
- A balloon drifting overhead may appear larger and farther away than it really is because it lacks obvious motion cues.
- A distant aircraft on a head-on approach can seem nearly stationary while producing less obvious sound than expected.
- A small drone may be assumed to be a much larger craft if its distance is overestimated.
- A glider can appear remarkably silent compared with powered aircraft.
The result is that silence does not distinguish between “small and nearby” and “large and distant”. Both possibilities can generate the same observation.
The Night-Sky Problem
Night sightings are especially vulnerable to this error.
When only lights are visible, observers often lose access to the shape, texture, and scale information that would normally help estimate range. A silent light may therefore be assigned an aircraft-like distance simply because it is seen in the sky. Once that assumption is made, a modest light source can be interpreted as a giant object. [AARO]aaro.milParallax effects cause the object to be.Read moreAAROEffect of Forced Perspective and Parallax View on UAP…As the airborne observer moves from position 1 to 2 to 3 in the air, they vi…
The witness may be reporting exactly what they experienced, yet the inferred size can still be dramatically wrong.
When Silence Really Is Relevant
Silence should not be ignored completely.
If a witness reports a large, apparently low-altitude object passing directly overhead for an extended period with no detectable sound, that observation is potentially useful. However, it remains only one piece of evidence.
Investigators must still ask:
- How was altitude estimated?
- Were there independent reference points?
- What was the background noise level?
- What were the weather conditions?
- Was the observation brief or prolonged?
- Did multiple witnesses report the same acoustic impression?
Without answers to those questions, silence alone cannot reliably support claims about extraordinary size or performance.
This is one reason modern UAP investigations increasingly emphasise sensor data. Human observers are valuable, but acoustic impressions can be distorted by environmental conditions and perception in ways that are difficult to reconstruct later. AARO’s discussions of perspective effects and the broader move toward instrumented observations reflect this problem. [AARO]aaro.milParallax effects cause the object to be.Read moreAAROEffect of Forced Perspective and Parallax View on UAP…As the airborne observer moves from position 1 to 2 to 3 in the air, they vi…
How Silence Should Be Handled in Reports
The most useful reports separate observation from interpretation.
Instead of writing:
“The object was silent, therefore it must have been enormous.”
A stronger report records:
- The object appeared silent.
- The observer’s location and surroundings.
- Estimated duration of observation.
- Whether traffic, wind, or other noise sources were present.
- Whether the object passed overhead or remained near the horizon.
- Any delay between visual observation and expected sound.
This approach preserves the evidence while avoiding assumptions that may later prove false.
For investigators examining IFO explanations, silence is best treated as a descriptive feature rather than a measurement tool. It may help narrow possibilities when combined with other data, but it cannot reliably determine distance, and without distance there is no secure basis for estimating size. That is why many apparently gigantic silent UFOs can ultimately trace back to a much simpler problem: the observer correctly noticed the absence of sound but incorrectly used that absence to infer scale. [AARO]aaro.milParallax effects cause the object to be.Read moreAAROEffect of Forced Perspective and Parallax View on UAP…As the airborne observer moves from position 1 to 2 to 3 in the air, they vi… [2eaglepubs.erau.edu]eaglepubs.erau.eduAeroacoustics of Flight Vehicles –noise propagation by refracting and sometimes focusing sound over longer distances.Read more…
Amazon book picks
Further Reading
Books and field guides related to Does Silence Mean A UFO Was Huge?. Use these as the next step if you want deeper reading beyond the article.
The UFO Experience
Useful for understanding witness reports where size and distance are uncertain.
The Invisible Gorilla
Explains how observers can misjudge what limited sensory evidence means.
How We Know What Isn't So
Rating: 4.0/5 from 6 Google Books ratings
Shows how confident conclusions can be built on weak cues such as silence.
Stick and Rudder: An Explanation of the Art of Flying
Provides useful context for how aircraft movement and distance can deceive observers.
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Endnotes
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Source: eaglepubs.erau.edu
Title: Aeroacoustics of Flight Vehicles –
Link: https://eaglepubs.erau.edu/introductiontoaerospaceflightvehicles/chapter/noise-of-flight-vehicles/Source snippet
noise propagation by refracting and sometimes focusing sound over longer distances.Read more...
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Source: aaro.mil
Title: Parallax effects cause the object to be.Read more
Link: https://www.aaro.mil/Portals/136/PDFs/Information%20Papers/AARO_Effect_of_Forced_Perspective_and_Parallax_View_on_UAP_Observations_2024.pdfSource snippet
AAROEffect of Forced Perspective and Parallax View on UAP...As the airborne observer moves from position 1 to 2 to 3 in the air, they vi...
-
Source: ntrs.nasa.gov
Title: Geometric Acoustics for Aircraft Noise Scattering (20220509)
Link: https://ntrs.nasa.gov/api/citations/20220006765/downloads/Geometric%20Acoustics%20for%20Aircraft%20Noise%20Scattering%20%2820220509%29.pdfSource snippet
NASA Technical Reports ServerGeometric Acoustics for Aircraft Noise Scatteringby Y Guo · 2022 · Cited by 17 — This paper discusses aircra...
-
Source: pmc.ncbi.nlm.nih.gov
Link: https://pmc.ncbi.nlm.nih.gov/articles/PMC11841372/Source snippet
Effect size estimation plots...
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Source: frontiersin.org
Title: Frontiers Soundscape Assessment of Aircraft Height and Size
Link: https://www.frontiersin.org/journals/psychology/articles/10.3389/fpsyg.2018.02492/fullSource snippet
FrontiersSoundscape Assessment of Aircraft Height and SizeDecember 18, 2018 — by G Memoli · 2018 · Cited by 9 — We propose a method to as...
Published: December 18, 2018
Additional References
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Source: x.com
Link: https://x.com/DoD_AARO/status/1788223137277952196Source snippet
X (formerly Twitter)Forced perspective and parallax are two optical illusions...Forced perspective and parallax are two optical illusion...
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Source: akroncantonairport.com
Link: https://www.akroncantonairport.com/assets/Noise-Study-Files/141030draftchapter2introductiontonoiseterminology1.pdfSource snippet
Akron-Canton AirportDraft Part 150 UpdateParticipants in airport noise studies often express interest in two sound-propagation issues: (1...
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Source: figshare.com
Title: Data Sheet 1 Soundscape Assessment of Aircraft Height and Size PDF
Link: https://figshare.com/articles/dataset/Data_Sheet_1_Soundscape_Assessment_of_Aircraft_Height_and_Size_PDF/7476914Source snippet
FigshareData_Sheet_1_Soundscape Assessment of Aircraft Height...17 Dec 2018 — For the first time, we report how the perceived visual hei...
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Source: researchgate.net
Link: https://www.researchgate.net/publication/388945514_Human_perception_and_response_to_sound_from_unmanned_aircraft_systems_within_ambient_acoustic_environmentsSource snippet
The results indicate that annoyance responses were influenced by UAS type...
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Source: theblackvault.com
Title: aaro explores forced perspective and parallax in new uap analysis paper
Link: https://www.theblackvault.com/documentarchive/aaro-explores-forced-perspective-and-parallax-in-new-uap-analysis-paper/Source snippet
When viewed from a moving vantage point, a stationary...Read more...
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Source: youtube.com
Title: Why UFOs Appear Silent: The Physics of Sound at a Distance
Link: https://www.youtube.com/watch?v=nO39n9S1qgESource snippet
Understanding Eyewitness Reports: The Silence Fallacy...
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Source: youtube.com
Title: Understanding Eyewitness Reports: The Silence Fallacy
Link: https://www.youtube.com/watch?v=52N1E74187sSource snippet
The Science of Why We Misjudge Objects in the Sky...
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Source: youtube.com
Title: Sound, Silence, and the Perception of Distance
Link: https://www.youtube.com/watch?v=uK8n_4P857gSource snippet
Why UFOs Appear Silent: The Physics of Sound at a Distance...
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Source: youtube.com
Title: Why We Mistakenly Assume Silent Objects are Large
Link: https://www.youtube.com/watch?v=S01Z2JvI-5ASource snippet
Sound, Silence, and the Perception of Distance...
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Source: youtube.com
Title: The Science of Why We Misjudge Objects in the Sky
Link: https://www.youtube.com/watch?v=W5y5K4-G5Z4
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