What is hidden hearing loss?
You may be surprised to know that some people experience hearing loss that can’t be diagnosed with standard testing. Hidden hearing loss is an umbrella term for any hearing loss that isn’t detectable by routine diagnostic testing.
Your ear is made up of three parts—the outer ear, the middle ear and the inner ear. The auditory system includes your ear, along with your brainstem and your brain, which each have a role in transforming vibrations in the air into the recognizable sounds and noise patterns that help you navigate daily life.
Hearing loss can include a number of different deficits, from peripheral auditory factors such as the common high-frequency sensory loss, which means high-pitched sounds are more difficult to hear, to central auditory issues with cognitive function (working memory or attention issues). High-frequency hearing loss can affect anyone of any age, but is more common in older adults with age-related hearing loss, as well as people exposed to loud noises.
What causes hidden hearing loss?There are many factors that may contribute to non-typical hearing problems. While the condition is more common in older adults (over the age of 65), hidden hearing loss affects all ages and is dependent upon the underlying mechanism and cause. For example, young adults with noise exposure experience it. In some cases, traumatic brain injuries may also cause hidden hearing loss.
How is hidden hearing loss diagnosed?You’ll start with a traditional hearing test if you’re having trouble with your hearing. You’ll also participate in additional testing such as speech testing in noise, high frequency audiometry testing and completion of a self-reporting questionnaire like the Hearing Handicap Inventory.
Hidden hearing loss was originally diagnosed as “psychogenic deafness,” because there was no evidence of auditory dysfunction, which suggested a non-organic hearing loss. In the 1990s, the term “auditory stress disorder” was suggested, although it never formally caught on. Now, we have sufficient evidence to suggest that hidden hearing loss is a multifactorial condition and patient complaints are real and have underlying explanations.
Is hidden hearing loss accompanied by other problems such as tinnitus?Tinnitus can be an early sign of hearing loss, but not always; people can have tinnitus without hearing loss. Almost 10 years ago, researchers suggested the use of the term “hidden hearing loss” and found that patients with clinically normal hearing but who experienced tinnitus might have reduced output of the auditory nerve at high levels due to neural damage or synaptopathy. Cochlear synaptopathy is the loss of nerve connections between the sensory cells and the brain, which occurs in noise-damaged and aging ears. The results are important to public health, because exposure to noise and ototoxic drugs may cause damage to your ear before it’s detectable in an audiogram.
How often do you see hidden hearing loss?We estimate between 5% and 10% of all patients who participate in testing at our audiology/ENT clinic have hidden loss.
How is hidden hearing loss treated?Several studies indicate that some patients with hidden hearing loss may see a mild improvement with open-fit hearing aids. Others have benefitted from FM systems, and general communication strategies to improve hearing, like lip reading and closed captioning.
What is the prognosis? Do people ever recover their hearing?While there’s currently no evidence of recovery, hidden hearing loss is an active research area in which drug therapy as well as auditory rehabilitation therapies are being explored to determine if hearing can be restored and recovered.
Melissa Schnitzspahn is an audiologist and Jason Riggs is a research scientist in the Department of Otolaryngology - Head and Neck Surgery at The Ohio State University Wexner Medical Center.