Only some people can hear this rumbling sound - but what is it?

Thursday, 20th February 2020, 2:08 pm
Updated Thursday, 20th February 2020, 2:09 pm

Users on social media have been baffled to learn that some people can voluntarily make a rumbling sound with their ears - and that some people can’t.

Twitter user @Rainmaker1973 posted an anatomical diagram of the inner ear alongside the caption, “A part of the human population can voluntarily control the tensor tympani, a muscle within the ear.

“Contracting this muscle produces vibration and sound. The sound is usually described as a rumbling sound”.

Sign up to our daily newsletter

The i newsletter cut through the noise

A part of the human population can voluntarily control the tensor tympani, a muscle within the ear. Contracting this muscle produces vibration and sound. The sound is usually described as a rumbling sound https://t.co/FjD36qFACU pic.twitter.com/ianKb60EK8

— Massimo (@Rainmaker1973) February 17, 2020

Many people have reacted with surprise to the tweet, shocked that some people can make the sound, while others were shocked that some people cannot make it.

I can do this! Woo! Didn’t know it was an uncommon thing. I have to close my eyes though...anyone else?

— Tom Carroll (Aspect Science) (@AspectScience) February 17, 2020

What is the tensor tympani?

The tensor tympani is a muscle near the ear canal in your skull. Scientists believe its job is to dampen the sound of loud external noises, like thunder, as well as internal noises, like chewing.

But, because of slight delays to its reaction time, the tensor tympani can sometimes fail to protect a person’s hearing from damage caused by extremely loud noises like explosions and gunshots.

How do I know if I can make the sound?

By tensing the tensor tympani quickly and tightly, some people are able to hear a low rumbling sound - like thunder - in their ears.

To see if you can do this, you need to tense the muscles in your face and neck - in a similar way to how you would tense your fist tightly.

Some people report that it is helpful to shut your eyes tightly while you do this. The fast twitch muscle fibres in the tensor tympani vibrate by contracting at up to 70 times per second, and can be heard against the eardrum.

While only some can manage this voluntarily, others can still sometimes hear the sound when the muscles of their neck and jaw contract tightly while they yawn.