Understanding Hearing Loss
The medical community has identified three types of hearing loss: conductive, sensorineural, and combined. Hearing loss affects your quality of life, health and social interactions, and how you treat it depends on its severity:
Table of Contents
- Conductive Hearing Loss
- Sensorineural Hearing Loss
- Combined Hearing Loss
Understanding hearing loss
Is it temporary or permanent?
It’s not easy to determine whether the inability to hear well is permanent (and might lead to deafness), a sign of a disease or disorder, or a symptom that will clear up on its own. It’s common for the ear to recover after brief noise trauma. One of the typical causes of permanent hearing damage is long-term exposure to loud noises. Many other factors, like nutrition, stress levels and natural ageing, also play a role in your hearing health.
Why hearing aids?
While no medicine can cure hearing problems, users can benefit hugely from wearing hearing aids. Today’s state-of-the-art solutions can deliver clear, natural sound quality and pair with your smartphone. It’s virtually invisible when worn and can have a positive impact on your overall health. Hearing aids fitted by a hearing care provider will never be too loud and won’t damage your hearing further. In fact, hearing aids are the only proven way to stop the progression of hearing loss.
Consequences of hearing difficulties
Hearing loss can make everyday tasks a challenge, and it can be frustrating when others don’t understand your listening situation. Your spouse, children, colleagues, and friends should know that hearing loss can have multiple effects on someone’s life.
- Social – Studies show that untreated progressive hearing loss can lead to depression, low self-esteem and social isolation, and make it difficult to concentrate.
- Physical – If left untreated, it can cause fatigue, exhaustion and headaches. There’s also a link between hearing loss and an increased risk of cognitive decline and dementia.
Conductive Hearing Loss
What is conductive hearing loss?
The eardrum and ossicles (middle ear bones) funnel sound waves through the air to convert it to action potentials or nerve impulses, which are carried to the brain. This process—known as transduction—is impaired in people with conductive hearing loss.
Conversations may feel strenuous for people with conductive hearing loss. Sounds are no longer sharp and clear, and they frequently report feeling like they have cotton wool or earplugs in their ears.
This type of hearing loss occurs when there are problems in the external ear canal or the middle ear. Possible causes include:
- Illnesses such as otosclerosis (abnormal bone growth in the middle ear)
- Cholesteatoma (abnormal skin growth in the middle ear)
- Inflammation accompanied by middle ear effusion (too much fluid) and scarring
- A build-up of cerumen (earwax), another foreign body or otitis externa (inflammation of the external ear canal)
- A fractured petrous bone (part of the temporal bone)
How is conductive hearing loss diagnosed?
Clinicians perform an otoscope exam to determine the condition of the external auditory canal (EAC), tympanic membrane (TM), and the middle ear.
Thereafter they will interpret the tympanometry results (test of middle ear functioning). This test looks at the flexibility (compliance) of the eardrum to changing air pressures, indicating how effectively sound is transmitted into the middle ear. This objective test also allows us to view the functioning of the Eustachian Tube, the upper auditory pathways and the reflex contraction from the middle ear muscles.
Impedance testing is crucial in distinguishing a conductive loss from a sensorineural hearing loss. A typical tympanometry result indicates the ear canal volume (cm3), the max pressure (daPa) and the peak compliance (ml). People with a conductive loss will have a Type B tympanogram suggestive of fluid in the middle ear. The result shows no identifiable peak and the ear canal volume is normal.
The Weber and Rinne tests can also be done in conjunction to the above. The clinician uses a tuning fork to strike and place on the crown of the head. People with normal hearing should perceive the sound from the Weber tuning fork equally in both ears, but for people with conductive hearing loss, it will sound louder in the affected ear.
Similar to the Weber test, the Rinne test also uses a tuning fork. This time, it gets placed on the mastoid bone behind the ear and the patient signals where they hear the sound the loudest. If it’s perceived louder in front of the ear then it’s called a Rinne + indicative of a Sensory neural or normal hearing but when they hear the sound louder behind the ear it’s called a Rinne- and indicative of a conductive loss.
Pure-tone audiometry is then performed which is the standard gold method of determining the type, degree, and configuration of hearing loss due to its widespread availability as well as inter-test reliability. Pure-tone audiometry distinguishes thresholds between bone and air conduction (the air-bone gap) to identify either conductive or sensorineural hearing loss. With a conductive loss the air conduction curve will be at higher decibel values than the bone. In other words, you require a significantly louder tone to hear sound waves carried through the air. This type of result warrants a referral to an ENT for further evaluation.
How is conductive hearing loss treated?
- Conductive hearing loss can be simple to treat if earwax is the culprit. Medication like decongestant nasal sprays can solve ventilation problems in the Eustachian tube (that connects the middle ear to the upper throat).
- In the case of secretory otitis media, a small eardrum incision can help drain excess fluid (paracentesis). If the problem occurs more frequently, especially in childhood, a specialist can insert a small tube (grommet) to remove the fluid, keep the eardrum open and prevent further inflammation.
- In more severe cases, such as otosclerosis or inflammation that have caused damage to the ossicles, specialists will consider more extensive treatment procedures. With stapes surgery or tympanoplasty, it’s possible today to replace or reconstruct the ossicles.
- Hearing aids are also an effective treatment for conductive hearing loss.
Sensorineural hearing loss
What is sensorineural hearing loss?
This type of hearing loss, also known as labyrinthine hearing loss, occurs when there is damage to the sound-sensing hair cells of the inner ear (cochlea) or the auditory nerve (which transfers sound from the inner ear to the brain).
One frequent cause is aging and the second most common is noise. Continuous exposure to noise volumes above 85dB (for six-eight hours a day) can result in sensorineural hearing loss. Other causes include circulatory problems, either because of diabetes, arteriosclerosis (hardening of the arteries), sudden hearing loss (SSHL) or metabolic illnesses such as thyroid malfunction.
People with sensorineural hearing loss complain of limited speech intelligibility. In its early stages, intelligibility is affected by background noise. Some may also suffer from ringing or buzzing in the ears (tinnitus). Prompt treatment is highly recommended to reduce the risk of social isolation and psychological changes.
How is sensorineural hearing loss diagnosed?
Audiometry tests can detect whether you have sensorineural hearing loss (damage to the nerve or cochlea) or conductive hearing loss (damage to the eardrum or the tiny ossicle bones).
An Audiologist may perform a series of tests:
Pure-tone audiometry examines the patient’s tone perception. You’ll listen to tones of varying frequency and volume and give a signal once you hear each tone. This creates the acoustic curve used to classify the type and degree of hearing loss. In cases of sensorineural hearing loss, the curve does not show any difference between bone conduction (tones transmitted through the bone) and air conduction (tones transmitted through the air from the eardrum to the inner ear). Both curves are positioned in higher decibel ranges compared to those of people with healthy ears.
Both the Weber and Rinne test looks at air and bone conduction. During the Weber test, people with sensorineural hearing loss will perceive the sound as louder in the healthy ear. With the Rinne test , a Rinne + (tone heard louder in front of ear) will be evident. This is indicative of a Sensory neural hearing loss. Another test that could give an indication of a Sensory neural hearing loss is the OAE (Otoacoustic emissions) test. The otoacoustic emission method involves sending a signal to the patient’s ear and measuring the reaction of the inner ear’s outer hair cells.
This test does not result in measurable emissions if the hair cells are damaged.
How is sensorineural hearing loss treated?
A suitable hearing aid is the best solution. Modern hearing systems are sophisticated minicomputers, packed with superior technology. Convenient features allow the devices to adjust to your immediate surroundings and detect a person’s voice from background noise. We at hear.com can help you find the hearing aids that are right for you and support you throughout the process.
Combined Hearing Loss
What is combined hearing loss?
When someone is diagnosed with combined or mixed hearing loss, they have both conductive and sensorineural hearing loss. Combined hearing loss may arise from a chronic middle ear infection or otosclerosis (overgrowth of bone in the inner ear).
However, multiple independent causes of conductive and sensorineural hearing loss may also be factors.
How is combined hearing loss treated?
The treatment method depends on the degree of hearing loss and its make-up. Specialists often prescribe medicine in mild or temporary cases, and hearing aids in moderate to severe cases. A bone conduction implant may successfully treat profound cases of combined hearing loss.
Today’s hearing aids are smart, discreet and so advanced it packs more power than the computer that landed the Apollo 11 on the moon. Bluetooth, rechargeability, smartphone connectivity and a range of incredible features have changed the way people think about modern hearing care. Learn more about hearing aids here.
What is tinnitus?
Tinnitus is the medical term that describes noise in the ears when no external noise is present. It affects between 10 and 20% of the population. People typically experience “ear noises” such as ringing, buzzing, hissing, deep humming, rustling, crackling or pulsing. It can be intermittent or constant, soft or loud and occur in one or both ears. Tinnitus can also lead to difficulty sleeping, poor concentration, headaches, and tension in the neck.
Ear noise sounds like:
Age, noise and the brain
While the exact causes are not fully known, age-related hearing loss and noise are two factors that are frequently linked to the condition. Older people are more likely to develop tinnitus, but it can also affect younger people. In the latter, it often occurs because of exposure to loud noise, like through headphones.
Acute tinnitus occurs when, for example, short-term exposure to excessive noise leaves the ears ringing or hissing for a few days. It appears suddenly and either goes away shortly after or remains for up to three months. In cases of chronic tinnitus, ear noises persist for a long time and can be distressing.
When sound enters healthy ears, sound signals are converted to electrical impulses and sent to the brain. A damaged auditory nerve will impact this spontaneous activity and may cause tinnitus. High noise levels can cause permanent damage to inner ear hair cells that transmit electrical signals to the auditory nerve.
Many other factors—earwax build-up, inflammation, certain medications, high blood pressure and head trauma—are connected to tinnitus. And while tinnitus without some degree of hearing loss is very rare, it can still occur.
Although it’s not yet known how exactly it results in tinnitus, stress is considered a major cause of intermittent tinnitus. Scientists are continuously looking for clues in the brain, to better understand tinnitus and hopefully find a cure for chronic sufferers.
Only the person with tinnitus can hear the ear noise. Subjective tinnitus is the most common type and can be linked to:
- Hearing loss (generally accepted as a factor)
- Sudden hearing loss (SNHL)
- Noise trauma
- Ear infections, such as otitis media or otitis externa
- Foreign bodies in the ear canal, such as a build-up of earwax
- Middle ear diseases, such as otosclerosis
- Viral and bacterial infections, such as Lyme disease
- Autoimmune inner ear disease
- Ototoxic substances, such as certain antibiotics
- A tumour that grows on the vestibulocochlear nerve (acoustic neuroma)
- Neck, teeth or jaw problems
- Diving accidents
If the examiner can also hear the ear noise, it’s known as objective tinnitus—a much more rare type.
- Breathing noises
- Artery or blood flow noise
- Middle ear muscle contraction
- Eustachian tube dysfunction
How is tinnitus diagnosed?
A specialist will examine the ears, nose and throat. They may also perform a subjective, an objective or otoacoustic emission hearing test, or test for a balance disorder. Other ways to diagnose tinnitus include a CT or MRI scan, a neck and jaw examination, or a blood test.
How is tinnitus treated?
Acoustic stimulation, behavioural therapy, medication, magnetic and electrical brain stimulation or physiotherapy can help treat tinnitus. Hearing aids won’t cure tinnitus, but can effectively mask ear noises and help patients manage their symptoms. It may also reduce the risk of tinnitus in people who have hearing loss but don’t experience ear ringing.
Tinnitus and hearing aids
When hearing loss occurs, the brain may lose its ability to process certain sounds and frequencies. Ear ringing may occur as the brain tries to fill the sound gaps. Modern hearing aid technology can help alleviate tinnitus both by treating hearing loss, as well as by using tinnitus maskers to cover up the sounds and help you focus on what you want to hear. Some of the hearing aid brands that are renowned for helping to alleviate Tinnitus are the latest Oticon and Widex ranges.
For example, Widex ZenTherapy helps you reduce the common negative effects of tinnitus, such as stress and sleep difficulties. Music and Zen sounds can help you relax, reduce stress, and prevent your tinnitus from flaring up. Widex Zen offers comforting sounds to help you avoid complete silence, and reduces your focus on the tinnitus.