New Auditory Device Grants Hard of Hearing Hope
As one of the five senses, hearing is an essential ability that many take for granted. However, according to the National Institutes of Health (NIH), about one in eight people ages 12 and up in the United States have suffered from some form of hearing loss in both ears. About 2% of adults aged 45 to 54 experience disabling hearing loss, and this proportion only increases with age. Once an individual is diagnosed with hearing loss, the effects are often permanent, with no cure for many types.
Normally, sound waves in the environment are detected by the auditory canal, a passage in the outer ear. Those sound waves then strike the eardrum, a section of the middle ear. This amplifies the sound waves which then reach the cochlea, a fluid-filled structure in the inner ear that’s lined with specialized hair cells known as stereocilia. Once the stereocilia receive energy from the sound waves, they convert it to electrical nerve impulses. Finally, these nerve impulses are received by the brain and nervous system, thereby allowing us to perceive or hear sound.
But those affected by the most common type of hearing loss, sensorineural (“inner ear”) hearing loss (SNHL), have damaged stereocilia or damaged nerve pathways. This can be caused by a variety of different circumstances, including physical deterioration over time due to aging, illnesses, deafness since birth, etc.
Although there are currently no cures for SNHL, advances in scientific technology have produced hearing aids, which improve one’s ability to hear and feel vibrations.
However, hearing aids often have low speech recognition and rely on external power sources. To address these issues, researchers have previously attempted to make nanogenerators, a type of small device that can convert mechanical energy forms like sound waves into electricity, which can act as nerve impulses, to mimic the auditory signals that stereocilia would normally receive. Although these studies had promising results, nanogenerators were high-maintenance, difficult to make, and could not always detect the sound frequencies used in human speech.
Normally, sound waves in the environment are detected by the auditory canal, a passage in the outer ear. Those sound waves then strike the eardrum, a section of the middle ear. This amplifies the sound waves which then reach the cochlea, a fluid-filled structure in the inner ear that’s lined with specialized hair cells known as stereocilia. Once the stereocilia receive energy from the sound waves, they convert it to electrical nerve impulses. Finally, these nerve impulses are received by the brain and nervous system, thereby allowing us to perceive or hear sound.
But those affected by the most common type of hearing loss, sensorineural (“inner ear”) hearing loss (SNHL), have damaged stereocilia or damaged nerve pathways. This can be caused by a variety of different circumstances, including physical deterioration over time due to aging, illnesses, deafness since birth, etc.
Although there are currently no cures for SNHL, advances in scientific technology have produced hearing aids, which improve one’s ability to hear and feel vibrations.
However, hearing aids often have low speech recognition and rely on external power sources. To address these issues, researchers have previously attempted to make nanogenerators, a type of small device that can convert mechanical energy forms like sound waves into electricity, which can act as nerve impulses, to mimic the auditory signals that stereocilia would normally receive. Although these studies had promising results, nanogenerators were high-maintenance, difficult to make, and could not always detect the sound frequencies used in human speech.
A cochlear implant is a device designed to improve hearing by processing external sounds.
Image Source: Maklay62
Therefore, researcher Yunming Wang and his colleagues sought to create a device that would mimic the function of normal stereocilia in humans and interpret sound at a broader range of frequencies. Additionally, they hoped that their product would be more efficient, easier to produce, and consist of material capable of both compression and friction to self-generate electricity.
First, they mixed tiny particles of barium titanate, a type of metal whose chemical structure favors sound vibrations, and coated them in silicone dioxide to create a material capable of conducting electricity. Then, they submerged the metal product in a solution to create a sponge-like membrane. The spaces inside the membrane would allow the barium titanate particles to bounce around as desired whenever sound waves hit.
After sandwiching their device between metal grids, the scientists concluded that their device was capable of detecting sound at a frequency of about 170 Hz, which is around the range of adult speech. Finally, they placed the device inside a model ear, played a music file, recorded the electrical output, and generated a new audio file to evaluate the performance of their device. The newly obtained audio file, which mimics what a human with the cochlear implant they produced would hear, was very similar to the original music file they played, indicating that their experiment was successful.
Overall, this research is extremely promising because it demonstrates that a cochlear implant can potentially operate electrically by itself without requiring an external power source while also being more efficient than before. For more than 13 million people, hearing is within sight.
First, they mixed tiny particles of barium titanate, a type of metal whose chemical structure favors sound vibrations, and coated them in silicone dioxide to create a material capable of conducting electricity. Then, they submerged the metal product in a solution to create a sponge-like membrane. The spaces inside the membrane would allow the barium titanate particles to bounce around as desired whenever sound waves hit.
After sandwiching their device between metal grids, the scientists concluded that their device was capable of detecting sound at a frequency of about 170 Hz, which is around the range of adult speech. Finally, they placed the device inside a model ear, played a music file, recorded the electrical output, and generated a new audio file to evaluate the performance of their device. The newly obtained audio file, which mimics what a human with the cochlear implant they produced would hear, was very similar to the original music file they played, indicating that their experiment was successful.
Overall, this research is extremely promising because it demonstrates that a cochlear implant can potentially operate electrically by itself without requiring an external power source while also being more efficient than before. For more than 13 million people, hearing is within sight.
Featured Image Source: mohamed_hassan
RELATED ARTICLES
|
Vertical Divider
|
Vertical Divider
|
Vertical Divider
|
