Hearing Loss
overview
Hearing occurs when a sound wave travels through the ear canal, causing vibration of the eardrum. Three small bones, called ossicles, are located on the other side of the eardrum. These bones transfer the energy from the eardrum to a fluid-filled structure in the ear, called the cochlea. This transfer of energy creates a fluid way in the cochlea, bending tiny hair cells that trigger an electrical stimulus of the hearing nerve, sending a signal to the brain. Hearing loss can occur if there is a disruption of the signal to the brain at any point along this pathway.
Hearing loss affects people of all ages, both children and adults. It is estimated that 2-3 of every 1000 children are born with hearing lossi. That number jumps to greater than 50% after the age of 70ii.
Hearing Loss
overview
Hearing occurs when a sound wave travels through the ear canal, causing vibration of the eardrum. Three small bones, called ossicles, are located on the other side of the eardrum. These bones transfer the energy from the eardrum to a fluid-filled structure in the ear, called the cochlea. This transfer of energy creates a fluid way in the cochlea, bending tiny hair cells that trigger an electrical stimulus of the hearing nerve, sending a signal to the brain. Hearing loss can occur if there is a disruption of the signal to the brain at any point along this pathway.
Hearing loss affects people of all ages, both children and adults. It is estimated that 2-3 of every 1000 children are born with hearing lossi. That number jumps to greater than 50% after the age of 70ii.
Symptoms
Symptoms of hearing loss can vary by age. Newborns with hearing loss may not turn their heads to track sounds or startle with loud noises. Toddlers with hearing loss often have a speech delay. Normal speech development is roughly 10 spoken words by 18 months and 50 or more words by 24 months.
One of the first symptoms experienced by adults with hearing loss is tinnitus, or a buzzing/ringing sound, in the ears. Adults with hearing loss often turn the volume on the television up, frequently require others to repeat what they say, and even sometimes will withdraw from social activities due to the embarrassment that can accompany hearing loss.
Causes
Hearing loss can be divided into the following three categories:
Sensorineural Hearing Loss
This occurs when the hearing nerve is not functioning properly. Most of the time this is due to decreasing signaling power of the cochlea. The cochlea is a snail-shaped structure behind the eardrum that detects a sound and sends an electrical signal to the hearing nerve. When this signal is decreased, patients have hearing loss. Genetic defects, congenital syndromes, age-related hearing loss, noise-related hearing loss, and medication side effects are some of the more common causes of sensorineural hearing loss.
Conductive Hearing Loss
This occurs when something is blocking the sound from getting to the hearing nerve. This could include the ear canal being obstructed by wax, a hole in the eardrum, fluid behind the eardrum, or problems with the bones behind the eardrum that pass the sound energy to the hearing nerve.
Mixed hearing Loss
A combination of both conductive and sensorineural hearing loss.
Symptoms
Symptoms of hearing loss can vary by age. Newborns with hearing loss may not turn their heads to track sounds or startle with loud noises. Toddlers with hearing loss often have a speech delay. Normal speech development is roughly 10 spoken words by 18 months and 50 or more words by 24 months.
One of the first symptoms experienced by adults with hearing loss is tinnitus, or a buzzing/ringing sound, in the ears. Adults with hearing loss often turn the volume on the television up, frequently require others to repeat what they say, and even sometimes will withdraw from social activities due to the embarrassment that can accompany hearing loss.
Causes
Hearing loss can be divided into the following three categories:
Conductive Hearing Loss
This occurs when something is blocking the sound from getting to the hearing nerve. This could include the ear canal being obstructed by wax, a hole in the eardrum, fluid behind the eardrum, or problems with the bones behind the eardrum that pass the sound energy to the hearing nerve.
Sensorineural Hearing Loss
This occurs when the hearing nerve is not functioning properly. Most of the time this is due to decreasing signaling power of the cochlea. The cochlea is a snail-shaped structure behind the eardrum that detects a sound and sends an electrical signal to the hearing nerve. When this signal is decreased, patients have hearing loss. Genetic defects, congenital syndromes, age-related hearing loss, noise-related hearing loss, and medication side effects are some of the more common causes of sensorineural hearing loss.
Mixed Hearing Loss
A combination of both conductive and sensorineural hearing loss.
Diagnosis
The following tests may be used to diagnose hearing loss:
Audiogram
This is performed in a sound booth. The participant is presented sounds at different pitches and loudness and notifies the examiner when the sound is heard. This is used to determine the type of hearing loss (conductive, sensorineural, or mixed), as well as the severity. In addition, hearing is evaluated by the patient’s ability to correctly identify words that are presented to them.
Tympanogram
A small insert is placed into the ear canal and emits a small burst of air. The device is able to measure the mobility of the eardrum.
Otoacoustic emissions (OAEs)
This device is placed in the ear canal and measures a signal sent from the cochlea. While this is not as accurate in determining the extent of hearing loss compared to an audiogram, it does not require patient cooperation/response and is therefore a great screening tool for newborn babies.
Auditory brainstem evoked response (ABR)
Stickers are placed on the head/scalp that measures brain activity in response to a sound stimulus presented to the patient. Patients are required to be resting comfortably; some infants are sedated for the procedure. Similar to OAEs, no patient cooperation/response is required. A benefit to ABR compared to OAEs is that more information is gained regarding the extent of the hearing loss.
Diagnosis
The following tests may be used to diagnose hearing loss:
Audiogram
This is performed in a sound booth. The participant is presented sounds at different pitches and loudness and notifies the examiner when the sound is heard. This is used to determine the type of hearing loss (conductive, sensorineural, or mixed), as well as the severity. In addition, hearing is evaluated by the patient’s ability to correctly identify words that are presented to them.
Tympanogram
A small insert is placed into the ear canal and emits a small burst of air. The device is able to measure the mobility of the eardrum.
Otoacoustic emissions (OAEs)
This device is placed in the ear canal and measures a signal sent from the cochlea. While this is not as accurate in determining the extent of hearing loss compared to an audiogram, it does not require patient cooperation/response and is therefore a great screening tool for newborn babies.
Auditory brainstem evoked response (ABR)
Stickers are placed on the head/scalp that measures brain activity in response to a sound stimulus presented to the patient. Patients are required to be resting comfortably; some infants are sedated for the procedure. Similar to OAEs, no patient cooperation/response is required. A benefit to ABR compared to OAEs is that more information is gained regarding the extent of the hearing loss.
Available Treatments
The treatment for hearing loss, in part, is determined by the type of hearing loss one has.
The following are treatment options for hearing loss.
Watchful Waiting
Appropriate in certain circumstances, such as when one has high-frequency hearing loss with preserved ability to hear normal conversation. Another example is someone who has hearing loss secondary to fluid behind the eardrum. Fluid behind the eardrum as a result of an ear infection will resolve in 3 months 75-90% of the time, making a wait and see approach reasonable prior to draining the fluid through a procedure.
Hearing Aids
Hearing aids may be an appropriate option for all three types of hearing loss. They are especially important in children with congenital hearing loss, or sensorineural hearing loss developed later in life. Hearing aids might not be the first choice for the treatment of certain types of hearing loss. Our providers will help determine the right treatment option for you.
Myringotomy With Tube Insertion
Commonly performed in children, but also performed in adults. Children with 3 ear infections in 6 months or 4 infections in one year that have retracted eardrum or fluid behind the eardrum on the exam are candidates for the procedure. In addition, fluid behind the eardrum lasting more than 3 months is commonly treated with ear tube insertion.
Repair Of Tympanic Membrane Perforation
A hole in the eardrum can result in hearing loss. This can result from trauma to the ear, a bad ear infection, or previous ear surgery. Repair of the perforation may range from placing a paper patch over the hole or taking tissue from behind the ear and placing it beneath the eardrum to help it heal.
Bone Anchored Hearing Aid
This is an option for patients with conductive hearing loss, or sensorineural hearing loss in one ear only. This type of hearing aid requires a metal post placed into the bone behind the ear. The hearing aid clips onto the post, causing vibration of the bone which stimulates the cochlea directly.
Cochlear Implant
This is an option for patients with severe to profound sensorineural hearing loss. An internal device is surgically placed into the cochlea. An external device is worn around the ear that transmits sound to the internal device, causing stimulation of the cochlea and hearing nerve.
Stapedectomy
Patients with a disease called otosclerosis develop a stiff stapes bone in the middle ear. This bone is important in transmitting the sound signal from the eardrum to the cochlea. When this bone is thickened, a procedure can be performed to restore sound transmission to the cochlea and drastically improve hearing.
Ossicular Chain Reconstruction
Three bones are located behind the eardrum that transmit the sound signal to the cochlea. In some situations, these bones can be damaged or eroded, causing a conductive hearing loss. This problem can be treated with a surgical prosthesis.
Treatment
The treatment for hearing loss, in part, is determined by the type of hearing loss one has. The following are treatment options for hearing loss.
Watchful Waiting
Appropriate in certain circumstances, such as when one has high-frequency hearing loss with preserved ability to hear normal conversation. Another example is someone who has hearing loss secondary to fluid behind the eardrum. Fluid behind the eardrum as a result of an ear infection will resolve in 3 months 75-90% of the time, making a wait and see approach reasonable prior to draining the fluid through a procedure.
Hearing Aids
Hearing aids may be an appropriate option for all three types of hearing loss. They are especially important in children with congenital hearing loss, or sensorineural hearing loss developed later in life. Hearing aids might not be the first choice for the treatment of certain types of hearing loss. Our providers will help determine the right treatment option for you.
Myringotomy With Tube Insertion
Commonly performed in children, but also performed in adults. Children with 3 ear infections in 6 months or 4 infections in one year that have retracted eardrum or fluid behind the eardrum on the exam are candidates for the procedure. In addition, fluid behind the eardrum lasting more than 3 months is commonly treated with ear tube insertion.
Repair Of Tympanic Membrane Perforation
A hole in the eardrum can result in hearing loss. This can result from trauma to the ear, a bad ear infection, or previous ear surgery. Repair of the perforation may range from placing a paper patch over the hole or taking tissue from behind the ear and placing it beneath the eardrum to help it heal.
Bone Anchored Hearing Aid
This is an option for patients with conductive hearing loss, or sensorineural hearing loss in one ear only. This type of hearing aid requires a metal post placed into the bone behind the ear. The hearing aid clips onto the post, causing vibration of the bone which stimulates the cochlea directly.
Cochlear Implant
This is an option for patients with severe to profound sensorineural hearing loss. An internal device is surgically placed into the cochlea. An external device is worn around the ear that transmits sound to the internal device, causing stimulation of the cochlea and hearing nerve.
Stapedectomy
Patients with a disease called otosclerosis develop a stiff stapes bone in the middle ear. This bone is important in transmitting the sound signal from the eardrum to the cochlea. When this bone is thickened, a procedure can be performed to restore sound transmission to the cochlea and drastically improve hearing.
Ossicular Chain Reconstruction
Three bones are located behind the eardrum that transmit the sound signal to the cochlea. In some situations, these bones can be damaged or eroded, causing a conductive hearing loss. This problem can be treated with a surgical prosthesis.
Services We Provide
- Audiogram
- Tympanogram
- Hearing Aids
- Myringotomy with tube insertion
- Repair of tympanic membrane perforation
- Bone anchored hearing aids
Services We Provide
- Audiogram
- Tympanogram
- Hearing Aids
- Myringotomy with tube insertion
- Repair of tympanic membrane perforation
- Bone anchored hearing aids
i Centers for Disease Control and Prevention (CDC). Identifying infants with hearing loss – United States, 1999-2007. MMWR Morb Mortal Wkly Rep. 59(8): 220-223. Vohr B. Overview: infants and children with hearing loss—part I. Ment Retard Dev Disabil Res Rev. 2003;9:62–64.
ii Lin, F. R. (2011). Hearing Loss Prevalence in the United States. Archives of Internal Medicine, 171(20), 1851. doi: 10.1001/archinternmed.2011.506