Why do tornadoes sound like trains? Undoubtedly, tornadoes tell you a fascinating tale of nature’s raw power.
Watching tornadoes twirling beautifully yet fiercely like skilled dancers in a grand performance is something special.
But, tornadoes can be devastating, and you cannot take that away from them.
And something that everyone would tell you about tornadoes is how frightening they often sound.
For some, the sound resembles a train. But, why do tornadoes sound like freight trains?
Tornadoes sound quite like trains because of echoing effects, low-frequency vibrations, and the interaction of air currents.
What Do Tornadoes Sound Like?
Some of nature’s most impressive and devastating phenomena are tornadoes.
These strong, spinning columns of the air have the potential to destroy entire neighborhoods, bringing down trees and tearing down buildings.
Many survivors have reported hearing a sound akin to a freight train during a tornado, which is one of the most defining features of these destructive storms.
How come tornadoes make the same noises as trains, though?
Understanding this phenomenon requires research into acoustics, tornado structure and dynamics, and the acoustic properties of freight trains.
Fact: The human ear has a wide frequency range of detection (20 Hz to 20,000 Hz), but is especially attuned to sounds between 1,000 and 5,000 Hz.
Tornado Structure and Dynamics
When air at the surface of the Earth is very warm and humid and rises to meet air at a higher, cooler, and drier altitude, a tornado can develop.
This causes atmospheric instability, which might trigger a thunderstorm.
Tornadoes can arise when wind shear, the variation in wind speed and/or direction with altitude, causes the rising air to rotate.
Tornadoes can cause anywhere from relatively minor damage to catastrophic loss of life and property.
Here, you need to understand that when anything vibrates, it causes a mechanical wave that can travel through a variety of different media, including air, water, and solids.
And the same happens when a tornado rotates.
Fact: Tornadoes can have rotating winds of 250mph and at that speed, the sound can be quite frightening.
Why Do Tornadoes Sound Like Trains?
Ask someone who has first-hand experience witnessing a powerful tornado, and they will confirm it sounds a lot like a freight train.
Okay, so you know a tornado sounds like train, but why is that?
Well, it could be because of the following reasons:
Low-Frequency Sound
Tornadoes and freight trains both generate deep, rumbling noises.
Tornadoes are so destructive because of the air’s rotation within the funnel and its impact on the ground.
Freight train noise is often produced by the engine and other mechanical parts and has a low frequency.
Humans have sensitive hearing and can detect low-frequency vibrations, which we often interpret as the rumble of a freight train or a tornado.
Wind Noise
Sound waves with a low frequency are produced by both tornadoes and freight trains.
In the case of tornadoes, this is due to the air’s spinning within the funnel and its interaction with the earth.
Freight trains’ low-frequency noise is largely generated by the engine and other mechanical parts.
That wind noise produced by tornadoes feels like a muffled sound coming out of a train, which is why many people associate it with a freight train.
Sound Reflection and Amplification
Tornadoes and freight trains both create tremendous amounts of noise, and any nearby buildings or trees will just serve to amplify and reflect that noise.
This amplification and reflection can heighten the perceived volume and intensity of the sound, further emphasizing the similarities between the two.
The Human Auditory System and Perception of Sound
The human ear is essential to our understanding of the sounds of natural disasters like tornadoes and freight trains.
Human hearing is optimized for sound frequencies between 1,000 and 5,000 Hz.
Though not as clearly perceived as sounds in our most sensitive range, low-frequency noises can nevertheless be detected.
Sensitivity to Low-Frequency Sounds
Our hearing is most acute in the middle-frequency range, but it also detects low-frequency noises, albeit with diminished accuracy.
Our brain interprets the low-frequency sounds made by tornadoes and freight trains as rumbling or roaring sounds.
As humans, we have an innate reaction to low-frequency sounds because we identify them with dangerous or powerful natural events like thunderstorms, earthquakes, and volcanic eruptions.
It means that your sensitivity to low-frequency sounds has a huge role to play in making a tornado sound like a freight train.
Localization of Sound Sources
In order to pinpoint the origin of any sound, our brain considers many factors, including:
- Loudness
- Frequency
- Duration of a sound play
Tornadoes and freight trains both create low-frequency sounds, and these can be trickier to identify than higher-pitched sounds, especially in noisy surroundings.
Because of this, our brains may interpret the sound as coming from all around us, or even engulfing us.
Factors Affecting the Perception of Tornado Sounds
Again, you need to understand that not everyone would agree that tornadoes sound like a train, and that is mainly because many factors are a play here.
For instance:
Proximity to the Tornado
The audibility of a tornado changes drastically depending on how close one is to the storm.
As one approaches a tornado, the sound becomes louder and more intense.
Moreover, as you approach the center of the vortex, the distinctive features of the tornado’s sound, such as the low-frequency rumble and the high-frequency wind noise, become more prominent.
The opposite is true as well: with increasing distance from the tornado, the rumble may become less audible and less pronounced.
Fact: When far away from a tornado, it is possible that individuals won't hear the telltale rumbling sound at all, and might only pick up on high-frequency wind noise.
The Presence of Other Noises
Environmental noises can dilute the impact of a tornado’s roar on our ears.
Tornadoes typically make a low, rumbling sound, although this might be hard to detect if the storm’s concomitant thunder, torrential rain, and hail are all present.
Human-made noises like traffic, construction, or other machinery can also interfere with our ability to hear the tornado.
When one sound is present, it might obscure the perception of another, a process known as auditory masking.
Extremely loud noises from the storm or the surrounding area might drown out the rumble of a tornado.
This leads people to incorrectly estimate its vicinity or perhaps fail to notice its presence altogether.
Atmospheric Conditions
To some extent, our perception of tornado noises is dependent on atmospheric factors, such as:
- Temperature
- Humidity
- The direction of the wind
Sound waves are able to travel farther than they would under normal atmospheric conditions thanks to the trapping effect of temperature inversions.
These inversions occur when a layer of warm air rests above a layer of cooler air near the ground.
It’s possible that someone further away from the tornado might still hear the rumble.
The Role of Topography
Similarly, topography affects the way in which sound travels through the atmosphere.
Tornadoes can be hard to hear in areas with steep mountains or hills because the landscape reflects or absorbs the sound waves.
Fact: Hills or other obstacles can block or scatter sound, making it more difficult to discern, whereas valleys can channel sound waves and magnify the noise.
Psychological Factors
The way our minds process and interpret tornado noises is also critically important.
It is possible for us to misinterpret or miss important aural cues because of the influence of our prior knowledge, experiences, and expectations.
Anticipation and Past Knowledge
People who are accustomed to the sound of tornadoes or have witnessed one in person may be better able to identify the distinctive rumbling noise.
However, those who are unfamiliar with tornadoes may not make the connection between the sound and the threat they pose, resulting in a delayed response or a lack of awareness.
Cognitive Bias and Pattern Recognition
Humans have an innate propensity to look for patterns where none exist in the sensory input we get.
This may cause some people to hear a tornado when none is nearby, or to mistake other sounds for the rumble of a tornado.
This mental flaw can alter how we interpret tornado sirens, leading us to either over- or under-react to the threat.
Takeaway
Why do tornadoes sound like trains?
Many people have compared a tornado’s sound to that of a freight train rolling by.
It is important to understand the intricate acoustics at play during a tornado occurrence so that we can fully comprehend the parallels between these two noises.
But, in most cases, tornadoes sound like trains because of their low-frequency sound, wind noise, and localization of sound sources.
