Auditory Recruitment – A Treatable Side Effect of Hearing Loss

Auditory Recruitment – also known as Loudness Recruitment – refers to a perceived rapid sound volume escalation in people with sensorineural hearing loss due to cochlear (inner ear) hearing cell damage. Even a small amplification boost can set off a fast and unexpected sound blast. Maybe this explains the observation that louder is not necessarily better for those with hearing loss.

The effects of Auditory Recruitment are akin to turning the radio or TV volume dial from “low/off” to “high” without any transition. Bam! Often accompanied by sound distortion, such crescendos can be very upsetting and startling to people. It is also understandable that Auditory Recruitment can complicate the setting and tuning of hearing aids.

Audiologists talk about a Narrow Dynamic Range, which means that the gap shrinks between what is hearable and what is tolerable. The more damage the cochlea sustains, the worse Auditory Recruitment becomes. And so, there are plenty of reasons why every effort must be made to preserve existing hearing and to not let hearing loss get worse.

More research is needed

Auditory Recruitment is said to be the result of damage to the cochlear (inner ear) hearing cells. Arranged in layers, there are two major types of cochlear cells with different assignments: The outer cell layers and the inner cell layers.

The outer cells amplify and modulate sound signals of low to moderate intensity. In a way, they make soft sounds “hearable.” The inner cells convert the adjusted sound signals into electrical signals. These electrical signals are picked up by the hearing nerve, which relays them to the brain for interpretation.

So far, damage to the outer cochlear cell layers is often said to be a root cause of Auditory Recruitment. The injured inner ear loses its sound-fine-tuning capabilities which can lead to unwelcome over-amplification following minor volume increases. But is that the whole story?  What is the exact mechanism underlying this complicated issue?

And so, researchers wonder about brain involvement and how cochlear trauma and sound modulation disturbances affect other hearing-related structures and nerve networks. There is so much more to know.

Auditory Recruitment sours quality of life

  Overall, Auditory Recruitment has a negative impact on mood and social interactions. It aggravates tinnitus. Social isolation becomes an issue. People stay away from louder venues because they anticipate sound surge discomfort and even pain. Sudden loud noises are especially problematic and scary.

Overuse of earplugs is common among those with Auditory Recruitment. While people try to make their lives more livable, they might actually make everything worse in the long run. Not only do they risk earwax accumulation, infections and inflammation but they also interfere with the free flow of sound and deprive the brain of necessary sound stimulation. The temptation to chronically stuff the ears should be an alarm signal that it is high time to find out what is really going on. Time to get help!

Get a diagnosis and a plan!

People who are beset by sudden sound surges need an audiologist who understands and acknowledges the issue. Hearing tests can tell a lot, including if hearing loss might contribute or if there is suspicion that some other condition could be at play. It is important to tell Auditory Recruitment apart from other sound sensitivities. Although some of the symptoms may feel the same, there are significant differences that a qualified audiologist can interpret correctly.

As already mentioned, Auditory Recruitment complicates the setting and tuning of hearing aids. Often referred to as sophisticated amplifiers, hearing aids are considered first-line treatment resources. Speak up if it is too loud! Audiologists can smooth the bothersome effects of a narrow dynamic hearing range with a sound processing technique known as compression.

Also, audiologists can advise patients on other methods, such as sound therapy and CBT (Cognitive Behavioral Therapy) that help them deal with the emotional and social fall-out of Auditory Recruitment.    

In the end…

Auditory Recruitment remains a complicated issue that is still not well understood. Although it is said that the overwhelming Recruitment loudness is perceived, those who have the condition can attest to “perception being reality.” Until more is learned through research and until better treatments become available, Auditory Recruitment remains a bothersome yet underrated side effect of hearing loss.