Background noise can make it hard for almost anyone to have a conversation.

However, if you have more trouble than others hearing and understanding conversations in a noisy environment, it could be a sign that you have hearing loss, or it may be a condition known as central auditory processing disorder.

“A person with a processing disorder is not able to process sound the way most of us do,” said Amy Boudin-George, clinician scientist and audiologist with the Defense Health Agency’s Hearing Center of Excellence, a branch of DHA’s Research and Engineering Directorate. “This leads to misunderstandings and difficulties in a lot of environments.”

“Children may be born with central auditory processing disorder,” said U.S. Navy Lt. Cmdr. Amanda Boudreaux, HCE U.S. Navy audiology liaison and acting clinical care section lead. “Adults can acquire a processing disorder from a traumatic brain injury or a blast exposure. There are studies that show some chemical exposures can also cause a processing disorder.”

According to the HCE, symptoms of an auditory processing disorder may include struggling to understand speech in noisy settings; problems recognizing spoken words or keeping up with telephone conversations; finding it hard to tell the difference between words that sound alike; and feeling uncertain about where the words you hear are coming from.

Hearing loss has similar symptoms, noted Boudin-George. “Having a traditional hearing test is the first step in diagnosing the problem. If no issues appear on that test, further evaluation may be warranted to differentiate between hearing loss and auditory processing disorder.”

Boudreaux added, “A processing disorder may occur with other hearing problems, but it is not the same as hearing loss. It may encompass multiple factors making testing and diagnosis more difficult.”

“I treated an active duty service member in a leadership position,” said Boudin-George. “He had been having trouble on the phone and in an office environment where the acoustics were poor. He found himself having to explain to people over and over again, ‘I'm so sorry, I can't really understand very well.’ He also had multiple things going on including a history of TBI. He was struggling a lot, but a standard hearing test showed near normal results.”

The complexity of sound can also play a role, added Boudreaux.

“Sounds are so complex, especially when it comes to speech. People with processing disorders may or may not have hearing loss, but they are not able to process those more complex signals,” said Boudreaux. “It's more difficult for us to diagnose because the more traditional auditory testing we do, such as a pure tone audiogram, a test that measures the softest sounds a person can hear at different pitches or frequencies, does not include those very complex signals.”

According to Boudin-George, psychological issues, or cognitive issues related to a TBI, can make it more difficult to pinpoint the problem. “It’s definitely important to be able to do more complex testing. It requires specialized training, and in some cases specific equipment, to be able to run these tests.”

Department of Defense Central Auditory Processing Working Group

In an effort to find solutions for these testing, diagnosis, and treatment issues, a group of clinicians and researchers from across the DOD and the Department of Veterans Affairs have come together to share their knowledge on auditory processing disorders and raise awareness.

“They’re able to share experiences in their clinical environments or research projects, go over results or methods, and get feedback,” said Boudin-George. “It’s a chance to move the ball forward in terms of identifying effective treatments, getting clinical tools and resources into the hands of clinicians, and making sure audiologists are able to probe further than the pure tone audiogram with extra tests if warranted for the patient.”

The group has developed resources to support clinicians, Boudin-George added.

“A few members of the working group published a paper in the Journal of Speech, Language, and Hearing Research in 2020, looking at the confounding effects that we've talked about with other disorders or diagnoses,” said Boudin-George. “It presents gaps in research, so potential funders could determine priorities for research funding in the future.”

A new peer-reviewed article in the same journal written by many of the same authors and Boudin-George came out in the summer of 2023, she added. “It provided information on the ‘state-of’ the science for auditory processing disorder treatment.”

“We can test, and we can diagnose all day long, but what do we actually do?” said Boudin-George. “The paper pulls together all the research done in the past several years, for service members and veterans in particular, on treatment.”

The working group also created a series of AudiologyOnline webinars for clinicians. Boudin-George said the webinars were developed based on feedback from the community about what they needed to get these practices into their clinics.

“We had presenters from the working group, all of them were volunteers, who shared their own clinical or research expertise. The webinars will be available through AudiologyOnline for the next three years.”

Boudreaux looks forward to having those resources accessible to active duty audiologists in the field. “The AudiologyOnline resource is a really helpful thing as we move around various facilities that may have different equipment or test batteries available.”

“We are really hoping to raise awareness of auditory processing disorders and get more support for evaluation and management across the DOD,” said Boudin-George. “Making these resources available can enable that to happen. It’s just one piece of the puzzle.”