How hearing works
Hearing is a complex process where many fragile parts of the ear work together to relay signals to the brain. Simply put, sound is captured by the outer ear and travels through the inner ear where sound waves are converted to messages that the brain understands:
- Sound waves enter the ear canal, moving toward the eardrum.
- Vibrations caused by the sound waves on the eardrum also causes the Malleus, Incus, and Stapes bones in the middle ear to vibrate.
- Tiny sensory hair cells within the cochlea capture the vibrations and transform them into electrical signals. Different sounds cause different types of vibration, which produce how loud we perceive a sound or the type of tone.
- The auditory nerve carries the electrical signals to the brain where they are understood as sounds.
Signs of hearing loss
Hearing loss may occur gradually over time or may be experienced suddenly.
The following symptoms may indicate that you should have your hearing checked by a hearing health professional:
- Occasionally thinking others are mumbling or speaking too softly.
- Having trouble hearing over the phone.
- Inappropriately responding to others after misunderstanding what was said.
- Frequently being told that your TV or radio is too loud.
- Constant roaring, ringing, or hissing in your ears known as Tinnitus.
- Finding it difficult to hear or understand conversations
with more than two people. - Needing others to repeat themselves regularly.
- Avoiding crowded places and restaurants because of difficulty hearing.
Degrees of hearing loss
According to Statistics Canada, 35% of Canadians report some type of trouble hearing or hearing loss. If you find yourself frustrated with your ability to hear, you are certainly not alone. As an individual loses the ability to hear, less sounds will be picked up by the ear and understood by the brain. The degrees of hearing loss ranges between slight, mild, moderate, moderately severe, severe, and profound. Normal hearing ranges between -10 – 15 decibels (dB). The following graph displays the degrees of hearing loss by decibels of hearing lost (dB HL).
