The fact that we’re able to hear sounds in our environment and process them almost instantly is nothing short of miraculous. Without even having to think about it, we can hear noises both loud and soft, near and far away. The pathway that these sounds travel in our ears is intricate, and if anyone of its parts isn’t working correctly, we can experience hearing loss.
Sound and Your Ear
Sound waves begin by entering your outer ear, called the pinna. It funnels these waves down your ear canal and into your middle ear, which is separated by the eardrum. The eardrum is a flexible membrane which begins to move when sound vibrations hit it, and that in turn starts to move three small bones in the middle ear: the hammer, anvil, and stirrup. These bones work together to amplify the sound waves and move them to your inner ear. The middle ear is where hearing loss begins to occur, so it’s important that all these moving parts are free of damage.
The inner ear is full of fine hair-like cells, replete with nerve endings, within a spiral-shaped organ called the cochlea. These tiny hair cells collect information from sound vibrations coming in from the middle ear and transmit those vibrations into nerve impulses (via the auditory nerve) to your brain. The brain processes and interprets these signals as sounds, allowing us to hear the noises around us.
Sensorineural Hearing Loss
The most common type of hearing loss, sensorineural hearing loss occurs due to a problem with the inner ear or auditory nerve. It presents itself when either the auditory nerve or the hair-like cells in the cochlea have sustained damage or are missing. This results in the inability to send complete nerve signals to the brain.
This kind of hearing loss can be caused by the following:
– Head trauma
– Drugs that are toxic to hearing (ototoxicity)
– Malformation of the inner ear
– Exposure to loud noise
Conductive Hearing Loss
Although rather uncommon and typically temporary, a conductive hearing loss can occur in some patients. It’s caused when an issue in the outer or middle ear blocks sound from the inner ear. Treatment involves the use of medication or surgery while other individuals opt to use hearing aids to improve their hearing ability.
Conductive hearing loss can be caused by:
– Ear infections
– Benign tumors
– Swimmer’s Ear
– Foreign object in the ear
– Fluid in the middle ear from colds
– Absence or malformation of the outer ear, ear canal, or middle ear
– Perforated eardrum
– Impacted cerumen (earwax)
Mixed Hearing Loss
When multiple parts of the ear’s anatomy are damaged, a mixed hearing loss can occur. In most cases, both the middle or outer ear along with the auditory nerve or inner ear have sustained an injury of some type or have encountered one of the conditions listed above. The conductive hearing loss present may be reversible while the sensorineural hearing loss is often permanent.
Auditory Processing Disorders
Rather than a hearing impairment which affects the ability to detect sounds, Auditory Processing Disorder (APD) causes individuals to struggle with their ability to organize, analyze, and interpret sounds around them.
For those with APD, all parts of the ear are functioning properly, but the auditory processing centers in the brain do not function normally. APD does not always include hearing loss and many times the treatments for this disorder versus a hearing impairment are dramatically different.
Hearing Loss FAQs
An audiologist is a primary licensed hearing healthcare professional who specializes in evaluating, diagnosing, treating and managing hearing and balance disorders.
A hearing aid dispenser (hearing aid specialist or dealer) is a person licensed to sell hearing aids and is limited to testing hearing solely for fitting hearing aids.
A hearing screening is a limited test to assess whether there is a hearing loss present by listening for soft sounds via headphones or insert earphones.
A diagnostic hearing evaluation is THOROUGH and gives more information about not only if a hearing loss is present, but also how much hearing loss is present, what part of the ear the hearing loss is originating from (outer ear, middle ear, inner ear, or nerve), and whether the hearing loss is permanent or correctable.