Hearing is the process by which the ear transforms sound vibrations in one’s external environment into nerve impulses sent to the brain, which interprets them as sounds. When vibrating objects produce pressure pulses of vibrating air molecules, otherwise known as sound waves, they produce sound. The ear can distinguish between different subjective aspects of a sound, like loudness and pitch, by detecting and analyzing the physical characteristics of waves. Sadly, cochlear damage can limit one’s ability to do so effectively.
Characteristics of Hearing
Pitch is determined by the frequency of sound waves, which is measured in cycles per second or hertz. For humans, the ear is most sensitive to and most easily detects frequencies from 1000 to 4000 hertz. However, younger children may be able to hear sounds all the way from 20 to 20 000 hertz.
Loudness is the perception of the intensity of sound, or the pressure exerted by the waves on the tympanic membrane (eardrum). The greater their amplitude/strength, the greater the pressure/intensity, and therefore the greater the volume, which is measured in decibels (dB). Human hearing ranges from 0 dB (almost inaudible) to 130 dB (at which point sound becomes painful).
The higher the decibel of a sound, the less time you should listen to it, as extended exposure may lead to noise-induced hearing loss (NIHL). Any sound over 85 decibels is considered dangerous to your ears and hearing. For example, a rock concert may reach sound levels of 115 dB, and just 15 minutes can cause cochlear damage.
The cochlea is the main organ of hearing and is located within the inner ear. Therefore, damage to it can lead to sensorineural hearing loss, which is typically permanent. Certain powerful antibiotics, meningitis, Meniere’s disease, acoustic tumours, aging, and loud/extended noise exposure (NIHL) can all cause cochlear damage. The only way to prevent NIHL is to limit exposure and to wear ear protection, such as ear plugs.
The cochlea has thousands upon thousands of “hair cells”, which are all responsible for picking up a different sound. They all work together to code the incoming sound and send it to the brain, in order to be heard and analyzed. The hair cells can be hit by loud sounds so hard, that they get bent, broken, or even sheared off. And because the hair cells in the cochlea cannot regenerate, the damage is permanent.
If only a few hair cells are damaged, there may only be a mild amount of hearing loss. This means the hair cells are there, but they need more sound before they can send it to the brain. In this case, hearing aids would work to amplify sounds. With a moderate amount of damage (and moderate hearing loss), hearing aids would work to amplify the sounds, although they may be distorted because of the damage. This can make it hard to hear in noisy places (e.g. mall), or hearing details in music. Hearing aids try to compensate by using techniques to sort background noise, or advanced digital processing to amplify sound. When severe cochlear damage occurs, sound coming in gets distorted by the hair cells, and because many hair cells are missing, a lot of sounds do not get sent to the brain. In this case, due to sound distortion, even very powerful hearing aids would be of limited help. This is where it may be recommended to get a cochlear implant.
Cochlear implants replace the hair cells by converting sound into electrical impulses which are relayed to the hearing nerve. Sound is picked up by a microphone on the ear, then sent to an implant under the skin using a radio frequency signal. There the implant converts the sound, and by placing a string of electrodes into the cochlea, the electrical impulses send the sound signal the hearing nerve, which is what the hair cells usually do.
If you’d like more information, or have any questions, please visit www.lifehearingsolutions.com, or call 289-755-0295 to book an appointment!
Advanced Bionics AG. What is Cochlear Damage? (n.d.). Retrieved on August 6, 2019 from
Higgins, J. (October 25, 2018). Anatomy of the Human Ear. Retrieved on August 6, 2019 from
Martin, L. (2014, August 20). [The cochlea in the ear, with damaged hair cells.]. Retrieved August 9, 2019, from http://www.observernews.net/2014/08/20/hearing-aids-cochlear-implants-and-hearing-loops/.