Doctoral student works to diagnose hearing impairments in children

Michelle Hsieh
Michelle Hsieh Photo: Sarah Wilson

This story originally appeared in On the Record, a publication of the College of Communication.

After Michelle Hsieh greets her research participants in the lobby of the Speech and Hearing Center in the College of Communication, she escorts them to a tiny room at the back of the clinic.

The room contains towers of electronic equipment with red blinking lights, wires threading along the floor and walls, and a giant steel chamber that looks like a bank vault with a window.

Inside the chamber -- called a sound booth -- Hsieh seats participants in a maroon recliner. After fitting them with earphones, she attaches electrode sensors to various points on their heads.

For two hours, she plays a succession of sounds -- oscillating beeps that resemble a toad croaking -- and asks them to remain motionless. She sits close by studying the readings from the sensors on her computer.

This is the audiology lab where Hsieh, a Ph.D. student in the Department of Communication Sciences and Disorders (CSD), conducts cutting-edge research in the field of electrophysiological audiology.

Hsieh pays her research participants -- normally undergraduate students -- $10 an hour to listen to specific sounds while she analyzes their brainwaves. "You play sounds into their ears, and sound generates neural activ­ity," said Hsieh. "Neurons will fire in a predictable way in response to that sound, and you can measure the response via the electrodes and know what it's supposed to look like, and obtain information about his or her hearing."

Hsieh said electrophysiological audiology holds tremendous potential for identifying hearing problems in infants and young children -- who can't participate in normal hearing tests.

In the normal tests, audiologists play specific sounds for patients and ask them to indicate when they've heard a sound by raising a hand or pressing a button. If the patient does not respond, the audiologist can tell the patient has a hearing problem.

But what if the patient is an infant or young child and unable to respond to the audiologist? Hsieh said the hearing impairment could go undiagnosed.

Early diagnosis is crucial, so doctors can begin treatment or teaching a child sign language. "A child with a hearing impairment from birth or at a young age due to illness has the chance of not being able to develop language," she said. "Language is the medium by which we interact with the world. You have to have language to be able to be a productive member of society and have meaningful relationships."

Currently, she is researching a specific "auditory steady state response" test to help determine how well a person hears timing and pitch. In addition to giving participants the electrophysiological test, Hsieh uses a variation of normal hearing tests -- what she calls "behavioral" tests. She then compares the data from the two to see if she can predict how their brainwaves should look.

Her research received the 2011 Student Researcher Investigator Award from the American Academy of Audiology, one of two $5,000 awards given to doctoral students nationally.

Originally from Richardson, Texas, Hsieh dresses casually in jeans and tennis shoes. At 27, she could be mistaken for an undergraduate rather than someone who is working on her second doctorate. When she finishes her Ph.D. in 2012, she will be the first person to earn two doctorates from the CSD department. Her first doctorate was in audiology -- called an Au.D. -- which enables her to diagnose and treat patients with hearing impairments.

A Ph.D. will enable her to conduct research on the hearing of infants and children, something she be came interested in at Dell Children's Hospital, where she works part time as an audiologist.

Craig Champlin, the chair of the CSD department and Hsieh's graduate advisor, said clinical experience can benefit a researcher. "I think it is a great arrangement because she is able to see on a daily basis where the holes exist in our knowledge base," Champlin said. "She sees a child that needs this test, treatment, intervention or diagnosis that we've never seen before, and it's something that she can study further in the controlled environment of the laboratory."

In addition to working on her second doctorate, she holds a bachelor's degree from the CSD department. When she graduates in 2012, she will have spent 10 years as a student at UT.

Hsieh said every semester she studies audiology, she finds it more fascinating. "In healthcare typically, there's something that goes wrong with your body somewhere, and then there will be a professional who specializes in knowledge of that part," she said. "What appealed to me about CSD was that what is impaired isn't just a body part, it's a way of life. It's the means by which we interact with our world."

Editor's note: This story has been updated to change "A child who is hearing impaired" to "A child with a hearing impairment" in an effort to address the person first and the physical condition second.