Tinnitus is a condition that affects millions of people and is commonly related to hearing loss. The common cause of tinnitus is caused by hearing loss or a traumatic condition that results in hearing loss itself. However, the truth is that tinnitus is not always directly linked or caused by specific hearing loss.
Hearing loss itself can often be present with tinnitus; however, the main cause of tinnitus is neural and can be found in the brain’s auditory cortex. For those with tinnitus, the condition can be everything from mild to severe and even life-altering.
“Tinnitus is one of those symptoms that may be frustrating, but it is important to have it checked by your healthcare provider. Often, there are some simple adjustments that can be made in almost everyone’s situation.” - Drew Sutton, MD, Board-Certified Otolaryngologist.
This is a comprehensive guide to everything you need to know about the basics of tinnitus: where does it come from, and are there different types of tinnitus? How do people acquire tinnitus, and are there any cures? How is it different from hearing loss, and what treatments can be sought?
Tinnitus - What Exactly Is It?
The ability to hear is a profoundly human experience. While those born without this fundamental ability can learn how to operate and interpret the world around them, it is considered a disability because society is not primarily built to service them. The learning curve involved in any kind of hearing loss, whether it was a profound hearing loss from birth or acquired hearing loss later in life, is substantial.
For many people, a part of their hearing loss journey is actually the presence of what is known as tinnitus. Tinnitus itself presents as a consistent sound or tone that occurs and is recognizable by the individual for no apparent reason. This sound can range in extremity and can be barely noticeable all the way to even deafening.
It also can present itself differently in sounds - for instance, some people describe their tinnitus as a consistent tone while others describe it as static or buzzing noise. Some have even described it as the sounds of crickets!
Tinnitus can also acutely present itself, and it can also be a chronic condition. There are two types of tinnitus: objective tinnitus and subjective tinnitus. For either condition, the initial onset of tinnitus can be overwhelming and even scary for the person who experiences it.
A person who experiences acute tinnitus and regularly with the condition lasting a set amount of time before dissipating and coming back either randomly or when provoked will struggle more than the person who experiences it chronically.
This is because the person who experiences chronic tinnitus can learn how to cope with the condition. In contrast, someone who experiences it acutely may not be able to build these skills as strongly due to the intermittent fashion of their tinnitus.
Tinnitus Is a Serious Condition
Tinnitus itself is a severe condition and can have far-reaching effects on the person who experiences it. If you are reading this article and you suspect or have been diagnosed with tinnitus, know that you are not alone.
The constant auditory recognition can cause a person to experience sleeplessness, anxiety, depression, and mental and emotional impact on their overall well-being. It is common also to share feelings of anger when dealing with tinnitus as the sensation of tinnitus is that you hear a sound that you should be able to block - however, no matter how much you insulate your ears, you still hear it.
This is a very important factor in understanding tinnitus because this issue isn’t caused by your ears at all.
Is Tinnitus a Form of Hearing Loss?
The question of whether tinnitus is a hearing condition or a result of hearing loss is a logical one as it appears that your hearing organs just won’t “shut off.” For a person who experiences tinnitus, the constant lack of quiet becomes the most challenging part of coping with and living with this condition.
However, the simple answer to this question is that hearing loss is not the cause of tinnitus, nor is tinnitus the cause of hearing loss.
Technically these two conditions, while most often seen presenting together, are not linked by causality.
Hearing Loss - A Quick Recap
Because tinnitus and hearing loss are so often considered to be either the same thing or directly linked, it will be beneficial to understand a basic overview of what hearing loss is.
Anatomy of the Ear
The ear itself is composed of three compartments that work together to help you interpret sound waves and understand these vibrations in a way that we call “hearing.” These compartments are the outer ear, the middle ear, and the inner ear. Each of these compartments is unique and plays a specific role in this process.
The outer ear is composed of the auricle, the external, visible, and commonly associated structure of the ear, and the opening of the ear canal itself. The auricle acts like a diverted dome that helps capture sound waves and directs them toward the ear canal to enter the hearing organ and be processed.
The middle ear comprises a tympanic membrane - commonly known as the eardrum - and a tympanic cavity. As the sound wave travels down the ear canal, it reaches the eardrum, or tympanic membrane, which causes unique vibrations unique to the frequency of the sound waves. These vibrations are transmitted to three tiny hearing bones in the tympanic cavity called the napes, malleus, and incus.
The inner ear is mainly composed of a snail shell-shaped structure called the cochlea. This structure has sensitive hair cells, and it interacts with the hearing bones of the tympanic cavity. It interprets the result of the vibrations from the tympanic cavity and translates them into electrical impulses.
From here, the auditory nerve takes these impulses to the auditory cortex for decoding, where the brain understands these messages as sound.
Three Types of Hearing Loss
When it comes to hearing loss, there are three general types of hearing loss that a person can experience: conductive, sensorineural, and mixed.
Conductive hearing loss is a general form of hearing loss that can cover many different causes and presentations. Sound is emitted from a source and travels through a medium, typically the air, as a vibration. This energy has a specific frequency, and these frequencies are uniquely signature to the particular sounds they produce. When a sound wave interacts with the outer ear, the auricle is structured in such a way as to conduct that sound wave down to the ear canal, where it can then pass through all three compartments of the ear.
Conductive hearing loss is when there is any barrier or problem with the conduction of that sound wave through the ear’s compartments. Many different factors and ranges can cause this, from mild symptoms to severe or even profound hearing loss.
For instance, a person could be experiencing conductive hearing loss if they have an excess of earwax buildup enough to hamper sound waves through the ear. This can present itself as sound being slightly muffled where the only treatment needed is an adequate ear cleaning.
This form of hearing loss can also be rather serious, such as when an autoimmune disease attacks the inner ear cells, causing discomfort. The inflammation can lead to complications with the transmission of sound through the ear, which qualifies as conductive hearing loss and can be severe.
Sensorineural Hearing Loss
Sensorineural hearing loss is hearing loss that deals specifically with the proceeds of the inner ear and the neurological side of hearing. The inner ear takes the physical results of hearing and translates those vibrations of energy into electrical impulses. That electrical impulse travels through the auditory nerve and interacts with the auditory cortex of our minds. Hearing loss develops when there is a problem with the ear’s ability to translate energy into electrical impulses; hearing loss develops, which is sensorineural hearing loss.
This form of hearing loss can result from chronic exposure to loud noises that over time damage the hair cells of the cochlea that do the work of translation. These hair cells do not have regenerative properties, and it is very important to protect your hearing from this kind of damage as it is permanent.
Sensorineural hearing loss can also be a result of trauma, or it can be acquired genetically. While a person can present with varying degrees of hearing loss who has sensorineural hearing loss, this form of hearing loss typically is more serious. Hearing aids and cochlear implants are both common forms of treatment for people who have sensorineural hearing loss, depending on the severity of their condition.
Mixed Hearing Loss
Mixed hearing loss is self-explanatory and is often seen in people experiencing hearing loss. Many people may suffer from both conductive and sensorineural depending on the criteria of their condition.
For instance, if they sustained trauma that damaged the cochlear functions of their inner ear while also producing swelling throughout the ear, this would qualify as both sensorineural and conductive hearing loss.
So Where Does That Leave Tinnitus?
As we have seen, these three types of hearing loss make up what we know as hearing loss itself. We don’t necessarily see that it can fit any of these categories when it comes to tinnitus.
So why, then, does tinnitus present as a sound? If it is not a part of hearing loss, and not expressly caused by hearing loss, how come it presents itself in a way that seems to be auditorily driven?
The simple answer is that hearing loss has to do with the ear as a sensing organ failing or struggling to do its part in the hearing process. While tinnitus seems to be related to the ear because the experience of tinnitus is ‘hearing a tone, hiss, or static sound’ that doesn’t seem to have a recognizable origin - the truth is, your ears are actually doing nothing to make this sound present.
Tinnitus symptoms might be a “sound,” but this sound has nothing to do with the ear’s function or lack of function. Tinnitus’s origin is in a particular part of the brain called a severe primary auditory cortex.
Anatomy of Hearing: From the Cochlea to the Auditory Cortex
When energy from sound waves reaches the cochlea in the inner ear, it interacts with hair cells found inside compartments of the cochlea called the Organ of Corti.
At this location, these specialized hair cells take that energy and translate it into electrical impulse where it interfaces directly with the vestibulocochlear nerve. From here the signal is carried to the brain, where it is interpreted at the primary auditory cortex.
The primary auditory cortex itself is located in the superior temporal gyrus and is arranged tonotopically. This is the area of the brain that is primarily used to interpret sounds into a recognizable format. The primary auditory cortex itself is very complex and spatially arranged to process different frequencies at different locations.
There Is No Real Silence
To understand tinnitus, we have to understand what real silence is. For many people, the concept of silence can be defined as the absence of sound. While this isn’t entirely wrong, it is fundamentally flawed. A more accurate statement would be that silence is the absence of ‘most’ sound.
The truth is if you were standing in a crowded subway terminal that had a natural amount of significant sound pollution, and you moved to a room that had no sound pollution - you wouldn’t be experiencing true silence.
You would notice a lack of stimulus to a dramatic degree, and it may seem like silence. Still, instead, your brain is just recognizing what it may see as a baseline of activity.
The brain’s baseline activity in the primary auditory cortex is naturally recognized as silence; however, it’s still an active state.
When stimulus from the ears comes in - the energy rises above that baseline. So when we are experiencing what our brains are interpreting as “silence,” we are experiencing the baseline neural activity that we recognize as silence. This baseline has a threshold that we may not consider, but it is set so that we can actually have peace of mind and enjoy ‘silence.’
Suppose we did not have this baseline neural activity. In that case, we may never experience silence or rest as we would be constantly introduced to stimuli like molecules colliding or even fluid moving through our ear.
Thankfully, this threshold means that small, minute sounds that happen below it - are not recognized. We can enjoy the silence and rest from what is happening, which is constant neural activity.
Tinnitus is thought to occur when one of the tonotopic areas of our primary auditory cortex is damaged. This can cause a lot of problems and can push this entire system out of harmony with itself.
Because the primary auditory cortex is arranged tonotopically, certain regions of the cortex understand and can translate specific frequency ranges. This is an incredibly complex and intricate system that we are still learning a lot about. An overly simplified example of this would be scale on a piano.
Every key plays a different note, and all the keys represent regions where that note can be produced. In a similar way, the regions of the primary auditory cortex represent areas where specific sounds can be recognized and understood.
When a person is experiencing tinnitus, they are experiencing problems in this area of the brain. Typically there is damage to a specific brain region that usually accounts for signal recognition of those frequencies. When this damage is present, another characteristic of the brain comes into play - plasticity.
Plasticity, put very simply, is the ability of the brain to compensate when a certain region is underperforming. So, suppose an area of the primary auditory cortex that recognizes frequencies in the mid-range is damaged. In that case, the areas of the cortex that recognize other frequencies will try to compensate. This can look like the other regions of the primary auditory cortex becoming more active to “make up” the region with clear deficits.
This is thought to be the cause of tinnitus. The sounds that we are ‘hearing’ aren’t coming from our ears but are instead actually coming from this damage to our neurology. However, when a region is damaged and other regions are overcompensating - this “silence signal” is not balanced correctly, and it results in a continuous tone with no apparent origin.
Being diagnosed with tinnitus usually involves a hearing test and can involve assessment by your physician. Most likely, your doctor can diagnose you based on your description of symptoms alone, as tinnitus is not uncommon and has a very distinct symptomatic presentation.
Unfortunately, there is no effective cure for tinnitus, and research is still being conducted to understand its origins and provocations better. While tinnitus can present with hearing loss, most treatments are not similar; however, there are certain conditions where devices like hearing aids could help.
Medications could also cause tinnitus and may need to come under your doctor's inspection. For people who have chronic tinnitus, noise suppression can be effective for mitigating tinnitus’ effects.
For instance, a white noise machine may not cut out a clear tone or "buzzing,” "clicking,” or "whistling" sound. However, it may mask the disorder to the degree that it can be ignored.
If you think that tinnitus is a constant stimulus above the ‘silence’ threshold of your neural activity, then adding another stimulation that has a soothing effect would counteract the initial stimulus. It would not negate or cancel out the tinnitus, but it may mask it and create a stable environment.
Another thing to keep in mind - is that tinnitus can have a heavyweight on a person's mental and emotional health. The feeling of helplessness can be exacerbated by a lack of sleep, resulting in emotional complications. Seeking medical advice and counseling on how to deal with your tinnitus is a great option.
The most important thing to remember when dealing with tinnitus is that you are not alone! This is a very serious condition that affects millions of people. While there may not be a clear cure, that does not mean that there is no treatment to alleviate your symptoms. Specialists like audiologists, ear, nose, and throat doctors around with neurologists can guide you along with professional counseling to help you regain control of your life.