How Hearing Works
To better understand how hearing loss occurs and the difference between sensorineural and conductive hearing loss, it is important to understand how hearing works. Your ear consists of the outer ear, middle ear, and inner ear. Sound starts by traveling down the outer ear’s ear canal and causing the eardrum to vibrate. These vibrations are picked by the three small bones in the middle ear where they continue to vibrate and cause fluid to move in the inner ear (cochlea). Tiny sensory hairs in the inner ear pick up on this movement and send electrical signals to the brain where the signal is processed as recognizable sound.
Sensorineural vs. Conductive Hearing Loss
Sensorineural hearing loss occurs when there is damage to the inner ear. The tiny sensory hairs in the inner ear are damaged and can not pick up on the vibrations and send them to the brain as effectively. Problems with the auditory nerve and pathways from your inner ear to your brain can also cause sensorineural hearing loss. Those with this hearing loss type have trouble hearing soft sounds, and loud sounds can be muffled and unclear. This is the most common type of hearing loss.
Conductive hearing loss occurs when there is damage or obstruction of the middle or middle ear. This prevents sound from traveling to the inner ear where it can finally be sent to the brain. Those who have conductive hearing loss often have more difficulty with the loudness of sound, but not the clarity. This is not as common as sensorineural hearing loss, but there are still many people who experience this type of hearing loss.
Both types of hearing loss can occur in only one ear, which is called unilateral hearing loss. It can also occur in both ears, which is called bilateral hearing loss.
Sensorineural Hearing Loss
Causes: There are many different causes of sensorineural hearing loss. The most common cause of sensorineural hearing loss is noise exposure. Repeated exposure to loud noise can damage our inner ear. According to the National Institute on Deafness and Other Communication Disorders (NIDCD), repeated exposure to noise above 85 decibels is dangerous and can lead to hearing loss. For your reference, 85 decibels is the sound of heavy city traffic or a lawnmower. However, exposure to loud noises is not the only cause of sensorineural hearing loss. Here are more causes:
- Ototoxic Drugs and Medications
- Presbycusis (Aging)
- Disease
- Genetics
- Traumatic Brain Injury
Symptoms include:
- Voices and sounds are muffled
- Trouble hearing when two or more people are talking
- Background noise makes hearing difficult
- Difficulty hearing women and children’s voices
- Ringing or buzzing in the ears (tinnitus)
- Dizziness and balance issues
Treatment: Currently, hearing aids are the most commonly recommended treatment for individuals with sensorineural hearing loss, and individuals with severe hearing loss may be candidates for a cochlear implant. Surgery and medications are not often effective for sensorineural hearing loss.
There are also other non-medical solutions on the market that help individuals cope. They include web and mobile application-based platforms for speech perception, recognition, audio training, and sound therapies hope to provide complementary solutions to provide relief and support.
Conductive Hearing Loss
Causes: Any factor that can affect the outer or middle ear could cause conductive hearing loss. Common and possible causes of conductive hearing loss can be:
- Malformation of outer ear, ear canal, or middle ear structure
- Fluid in the middle ear from colds
- Ear infection (otitis media – an infection of the middle ear in which an accumulation of fluid may interfere with the movement of the eardrum and ossicles)
- Allergies
- Poor Eustachian tube function
- Perforated eardrum
- Benign tumors
- Impacted earwax
- Foreign object in the ear
- Otosclerosis
Symptoms include:
- Difficulty in hearing speech
- Sensation of pain in one or both ears
- Sensation of pressure in one or both ears
- Strange odor from the ear
- Your own voice sounds different
Treatment: Treatment options for conductive hearing loss can vary depending on what the cause of your hearing loss is from. Surgery could correct conductive hearing loss that is due to the congenital absence or dysfunction of ear structures, otosclerosis, and tumors. Other medical procedures and treatments can help with impacted earwax, foreign objects stuck in the ear, ear infections, and ear fluid.
Hearing aids can also be an effective treatment for those who have conductive hearing loss. Depending on the status of the hearing nerve, a normal hearing aid will do or a special bone-conduction hearing aid could be more beneficial. Bone conduction hearing aids will help amplify sounds, great for people with conductive hearing loss who have harder time with the volume of sound than the clarity.
We hope you enjoyed our article on the differences between sensorineural and conductive hearing loss. It is very important to protect your hearing health by maintaining safe volume levels, staying healthy, and reducing risk. If you experience hearing loss, it is important to visit a hearing professional to understand what kind of hearing loss you have and the best course of action to take.
AudioCardio is a technology company focused on hearing health and wellness. Learn how AudioCardio can help maintain and strengthen your hearing with your favorite headphones or hearing aids at www.audiocardio.com.
References
- https://med.uth.edu/orl/online-ear-disease-photo-book/chapter-3-ear-anatomy/ear-anatomy-outer-ear/
- https://www.cdc.gov/ncbddd/hearingloss/types.html
- https://www.hearingloss.org/hearing-help/hearing-loss-basics/types-causes-and-treatment/
- https://www.mayoclinic.org/diseases-conditions/hearing-loss/symptoms-causes/syc-20373072
- https://www.nidcd.nih.gov/health/noise-induced-hearing-loss
- https://www.nidcd.nih.gov/health/sudden-deafness
- https://www.healthyhearing.com/report/50276-Common-causes-of-sensorineural-hearing-loss
- https://www.asha.org/public/hearing/Sensorineural-Hearing-Loss/
- https://www.dizziness-and-balance.com/disorders/hearing/sensorineural.htm
- https://www.hearingloss.org/hearing-help/hearing-loss-basics/prevention/
