THE human body is an astonishing feat of nature, with intricate parts coming together to give us
senses that allow us to perceive and interact with the world around us in detail.
We see with our eyes, smell with our nose, taste with our mouths, and hear with our ears... except that the last one might not be the entire truth.
Research suggests that humans have two ways of processing auditory information – the first being via our ears, and the second, lesser-known way being through the skull.
Is it true that we can ‘hear’ beyond our ears through the bones in our skull?
Verdict:
TRUE
Traditionally, we understand hearing as the pathway involving our ears capturing acoustic waves
from our environment, also known as air conduction.
As these waves travel down the ear canal, they cause the eardrum to vibrate. The vibrations are
then transmitted through tiny bones in the middle ear and converted into electrical impulses by the cochlea in the inner ear, which the brain interprets into what we perceive as sound.
However, the eardrum does not necessarily need to vibrate for us to ‘hear’ a sound; other methods of making the bones in the inner ear vibrate can also be interpreted by the brain as sound.
This is known as bone conduction and is why it is possible to hear a mechanical watch ticking if you hold it between your teeth – try it!
Bone conduction technology has been in use for a good while, arguably as early as the 15th century, when it was put into practice by physician Hieronymus Capivacci, who used the concept to diagnose hearing disorders in his patients.
Revered pianist Ludwig van Beethoven, who suffered from hearing loss, reportedly used a metal or wooden rod to transmit the vibrations of his piano to his skull, biting one end between his teeth and touching the other to his piano as he played.
As for the average, hearing person, bone conduction plays a role in how we perceive our voice
compared to how others hear us.
If you have ever wondered why your voice sounds different when it is recorded, it’s because we are used to hearing our voice partially through our skull, from the vibrations of our vocal cords!
More recently, this principle has been harnessed in the development of bone conduction
headphones, which have a unique open-ear design, making them safer for use in busy public spaces.
Unlike traditional earphones and headphones, these devices do not obstruct the ears at all. Instead, they are placed on the temples and transmit sound directly to the inner ear through the skull.
This technology is especially useful for individuals with certain types of hearing loss, outdoor
athletes who need to stay aware of their surroundings, and even military personnel in combat
situations.
Despite the effectiveness of bone conduction, it is not a complete substitute for the traditional
hearing pathway.
Air conduction provides a wider range and clarity of sound, which is why it remains the primary way we experience audio. Bone conduction, on the other hand, is generally better at transmitting lower-frequency sounds and can be less clear when it comes to higher frequencies.
In a medical context, hearing aids with special vibrators are sometimes prescribed to patients with middle-ear disease or disorders of the eardrum. However, this will not work if the patient’s hearing loss is due to nerve damage or deterioration.
Sources:
1. https://hearinghealthmatters.
2. https://www.imperial.ac.uk/
3. https://www.
4. https://www.zmescience.com/
