Understanding Speech in Complex Listening EnvironmentsDawna Lewis, Ph.D.Director, Listening and Learning Laboratory
The work that I do, in the listening and learning lab, focuses on children who have unilateral hearing loss or mild bilateral hearing loss.
Bilateral hearing loss means that you have hearing loss in both ears so in our case these children have what would be considered a mild degree of hearing loss but it occurs in both ears. A unilateral hearing loss is a hearing loss in which hearing is completely normal in one of your ears but you have a hearing loss that could be of any degree in the other ear.
I’m interested in this population because they are a group of children with hearing loss that represent as much as five percent of the school-age population and that might not sound like a lot children but in numbers that’s as many as three million children in the school-age population who have hearing loss and the research in the past has shown that these children perform more poorly than their peers with normal hearing.
We are interested in examining in complex listening environments like classrooms what are the underlying factors that are really playing a part in the difficulties that these children are experiencing.
We designed the lab to enable us to do multiple different tasks that allow us to adjust the acoustics. We have an innovative head tracker that they wear on their head that allows us to monitor that looking behavior in a very fine grained way. Those together give us a little more information about how this looking behavior in the children is affected by the acoustic environment.
The current tasks that we are doing, that the talkers are being shown individually, so the screens are blank until the talker begins to speak, and then that talker appears on the screen for that particular task. So we have the flexibility to adjust the audio visual stimuli based on what the question we are asking for that particular study and that particular task.
Another study that we are doing to look at how children understand speech that’s degraded is going to be conducted in this space and here they’ll be listening to very degraded speech which is speech sounds kind of like R2-D2 talking or speech that we’ve added some modulation to give it a little more grouping so that it sounds more speech like and then real speech in noise.
That information will help us when we think about children trying to listen to speech in the world where some talkers are much clearer than other talkers where background noise can interfere with your ability to hear all the components of speech. How well can you take the information that’s available to you and use that information?
The overall goal of my research is to really understand the factors that impact real world communication for these children which in turn will allow us to develop the strategies that we need to provide them with access and to give them the same opportunities and the same availably of information as their peers with normal hearing have.
Under the direction of Dawna Lewis, this research study aims to improve communication access for children with minimal/mild hearing loss in complex learning environments, such as classrooms. The research from this project aims to help establish factors affecting the difficulties a child with minimal/mild hearing loss will encounter when trying to listen and understand speech in the real world.