There are many things that we can do as humans, but there are also many things that we can’t hear. Since our hearing range is only 20 to 20,000 Hz it’s impossible for us to hear many frequencies. Compared to animals we are oblivious to a huge number of sounds in the world. If you don’t believe me check out this hearing test:
(You’ll need your earphones for this)
Luckily for us though, we are able to distinguish other sounds through a range of scientific instruments that can analyse specific frequencies. If it weren’t for these tools we wouldn’t even know they exist!
So, check out these 5 sounds which you probably can’t even hear:
1. Elephant calls
In order to be able to interact with each other, elephants use infrasonic sounds – low frequency noises that range between 1 to 20 Hz. A study conducted by elephant expert William Langbauer in Africa, showed that the infrasound ‘silent call’ of these animals can be transmitted over long distances (up to 10 km) and can even travel through leaves, trees and air. These sounds help them to communicate with each other while travelling in separate groups in the wild.
2. Ultrasonic finger friction
Apart from low frequencie sounds, there are also some really high-pitched sounds that cannot be heard by humans. These are called ultrasonic frequencies or ultrasounds and can be produced and heard by bats and dolphins. When you rub your thumb and index finger together, the friction creates an ultrasonic sound that’s often used to test the function of a bat detector. This adjusts the frequency of the sound so that humans can hear it too. According to entomologist Gilbert Waldbauer, this action can train bats to respond to the sound and fly towards it.
3. Piano tunes designed for cats
This unique piano plays ultrasonic frequencies that are designed specifically for cats’ ears. This instrument can produce some sounds that humans can hear – depending of course on their age and sensitivity to sound, but at the same time it can transmit wider frequencies that only cats can hear. So, if you want to set up your own cat choir, perhaps this is the way to go.
4. Volcanic eruptions
An earthquake before a volcanic eruption creates a harmonic tremor which is basically a continuous release of infrasonic sound that’s caused by the movement of the lava. Using an electret condenser microphone, scientists were able to identify the sound and record the volcano’s infrasonic emissions which they sent for further analysis. This discovery has helped scientists to understand what happens before the eruption of a volcano and get more information in regards to its eruption cycle.
5. Nuclear Tests
Fourteen years ago, the Prepatory Commission for the Comprehensive Nuclear-Test Ban Treaty Organisation (CTBTO) started creating infrasound stations that measured the low-frequency sound waves nuclear weapons made so that it could identify secret nuclear testing activities. Today, this infrasound technology helps the International Monitoring System (IMS), keep track of such signals just like it did in 2009 by pinpointing down the location and the size of North Korea’s first successful nuclear test.
This world holds many mysteries and keeps a great deal of information away from us – and our ears! With science though, we have managed to determine ridiculously low and high-pitched sounds that were once impossible for us to hear.
If you want to get more information about human hearing range, check out this video from AsapScience above that explains how hearing abilities can change over the duration of our lives indicating that some sounds may not be as obvious to us as we grow up.
Are you aware of any other sounds that as humans we can’t hear? Let us know in the comments section below…