Communication Disorders Receives $140,000 Grant

Published on May 03, 2016

Written by Bethany Broderick

The Department of Communication Disorders received a $140,000 grant from ReSound, an international hearing solutions company, to create an alternative metric for pediatric hearing aid fittings. The two-year study—led by Dr. Kelli Watts, assistant clinical professor, along with Professors Emerita Dr. Sandra Clark-Lewis and Dr. Judith Blumsack—will demonstrate how head circumference affects a child’s ear canal acoustics, providing audiologists with a more accurate metric for pediatric hearing aid fittings. 


The shape of the external ear canal enhances specific frequencies. The smaller the child, the smaller the ear canal; and the smaller the ear canal, the louder some of these frequencies are between the hearing aid and the eardrum. When a child is fitted for a hearing aid, an audiologist should first measure each child’s ear canal acoustics. This measurement, called the real-ear-to-coupler difference (RECDs), reveals which frequencies are enhanced or diminished by that child’s ear canal shape. The audiologist then uses these values to program the hearing aid to the child’s hearing loss, compensating for the frequencies that are not sufficiently resonated by the child’s ear canal.

But there are situations where audiologists may not be able to measure a child’s ear canal acoustics, such as when a child has experienced pain from past ear infections, has a developmental or mental disability, or is uncooperative. In these cases, audiologists use the industry standard metric based on age to determine the target range for the hearing aid.

The current age-based metric was devised by researchers at the University of Western Ontario, Canada. However, faculty at Auburn University began to notice issues with the age-based metric when the Auburn Audiology Guatemala Outreach Project began in 2009. Because the industry’s age-based averages were based on healthy, Canadian children, the averages were too large for the malnourished and underdeveloped children in Guatemala.

Kelly Watts
Dr. Kelli Watts

“There was a real discrepancy between the age-based norms and what we were getting when we measured the RECDs of Guatemalan children’s ears,” explains Watts. “A couple years ago we did a pilot study and wanted to see if there was a better metric than age to estimate ear canal acoustics. We looked at height, weight, and head circumference and found that head circumference was a much more reliable measure even than age.”

With this new knowledge, Watts, Clark-Lewis, and Blumsack designed a larger study to develop an alternative standard to the age-based averages; however they needed funds to develop their metric by measuring the RECDs of hundreds of pediatric ears. When they presented their study to ReSound, one of the largest hearing aid manufacturers in the world, ReSound agreed to provide the Department of Communication Disorders with a $140,000 grant to establish new normative data based on head circumference instead of chronological age.

“We have a long-standing relationship with Auburn University, supporting their annual missions to Guatemala. They have an incredible group of dedicated professionals and students that share our passion for helping people rediscover hearing. Which is why we believe that evolving that relationship to also financially support this type of research is so vital. It further advances our mission to ensure that, together with the audiology professional,  we’re offering the best possible solutions to help people hear more, do more and be more,” said Kim Lody, President of ReSound.

The grant will provide Watts and her team with new equipment and three graduate research assistants over a two-year period. In the first year, Watts’ team will collect data at the Columbus Speech and Hearing Clinic in Columbus, Georgia, and a team from the University of Western Ontario will assess children in Canada. After developing a metric from this data, in the second year, Watts will return to Guatemala to see if the metric works with smaller, malnourished children. 

Auburn Audiology students with Guatemalan children

“We want to develop a metric that is not just a North American metric, but one that would be more universal and could be used in hearing aid fittings around the world,” said Watts.

An accurate hearing aid fitting is imperative for children with hearing loss. If a child is under-fit (not enough sound), they may struggle with acquiring language, understanding in classroom and social settings, and avoiding environmental dangers. If they are over-fit (too much sound), the child may become uncomfortable and refuse to wear the device, or the aid may cause more hearing damage. This new standard will allow audiologists all over the world to more accurately fit children with hearing aids when they are not able to measure a child’s ear canal acoustics.

“Communication is such an important part of life—whether it’s for school, work, or survival—and we want to make sure they have full access to all sounds,” said Watts.  

Written by Bethany Broderick, graduate assistant in the Office of External Affairs for the College of Liberal Arts at Auburn University.