Hearing loss is a complex health condition with multiple causes and subtypes. Traditionally, hearing loss has mostly been understood as being sensorineural—occurring due to a dysfunction in the inner ear—or conductive—occurring due to a dysfunction in the outer or middle ear. However, a new understanding has emerged that introduces a new type of hearing loss: hidden hearing loss.
How Hearing Works
Let’s quickly review how hearing works. Sound waves enter the outer ear and travel through the ear canal and into the middle ear. Tiny bones in the middle ear amplify and then channel those sound waves into the inner ear, where sensory cells within an organ called the cochlea encode the sound waves into electric signals. These electric signals are then carried up to the brain through the auditory nerve, and the brain processes those signals into a sound that we hear.
The Traditional Types of Hearing Loss
As mentioned, the two traditional subtypes of hearing loss are sensorineural and conductive. Sensorineural hearing loss originates from an issue with the inner ear, such as damaged sensory cells in the cochlea or malformations in the inner ear. Conductive hearing loss is caused by an issue with the outer or middle ear, such as an ear infection, impacted earwax or perforated eardrum.
In both sensorineural hearing loss and conductive hearing loss, something known as the auditory threshold changes. Your auditory threshold is the lowest level of sound that you can detect, taking into account both volume and pitch. When your auditory threshold rises, as is the case with both sensorineural and conductive hearing loss, some sounds you could hear previously fall below the threshold, and you lose the ability to hear them.
Hidden Hearing Loss
Hidden hearing loss is different from sensorineural and conductive hearing loss. With hidden hearing loss, one’s auditory threshold does not change. Instead, while the ear and its organs gather and transmit sound information as normal, the ability to process the sound signals is impaired. The result is that one might hear everything (i.e., pick up the sound information and perceive it; no sound signals are unheard) but struggle with listening comprehension and acuity. Hidden hearing loss is especially noticeable in noisy situations, like walking down a busy street or in a crowded restaurant.
Our understanding of hidden hearing loss is still developing, and much more research is needed, but what we do know has changed common perceptions of what hearing loss is. It also has major implications for how we test for, diagnose and treat hearing loss.
Getting Help for Hearing Loss
If you struggle with hearing, either because you miss sounds entirely or because you struggle to follow along in settings with complex listening conditions, it’s time to visit a hearing health specialist for a hearing test. There are several types of hearing tests, each able to detect different facets of hearing ability. A pure tone test, for example, will find sensorineural or conductive hearing loss, while a speech test is better suited for testing for hidden hearing loss. Our experts at PDX ENT can perform these tests and more, helping you get the answers you need and the customized hearing treatment plan you deserve. Call today to make an appointment.
