Dr. Ferenc Bunta, assistant professor in the Department of Communication Sciences and Disorders at the University of Houston (UH), was awarded a $450,000 grant from the National Institute on Deafness and Other Communication Disorders (NIDCD) to study phonological acquisition in bilingual children who use cochlear implants. Currently, this population is underserved because little is known about their speech and language development and there are no existing measures that can assess their abilities accurately. Bunta and his research team are working in collaboration with Dr. Jennifer Wickesberg, adjunct assistant professor at UH and Director of Audiology at The Center for Hearing and Speech, to investigate how bilingual children with cochlear implants develop speech and language.
What is a cochlear implant? How does it help an individual hear?
A cochlear implant consists of five distinct elements that allow its user, who has sensorineural hearing loss, to perceive sound. The internal elements include a receiver that is placed on the skull just under the scalp and an electrode array that is surgically inserted into the cochlea, or inner ear. Externally, a user wears a speech processor with a microphone that looks like a traditional behind-the-ear hearing aid. The microphone gathers sound and sends the signal to the speech processor, which then digitizes the sound and sends it to a transmitter worn on the scalp via a magnet that positions the device directly over the internal receiver. The transmitter then sends the digitally coded sound to the receiver, which delivers the digital signal to the electrode array. Finally, the electrodes stimulate the auditory nerve, which allows the cochlear implant wearer to perceive sound.
Who is your target population?
We are studying bilingual Spanish-English-speaking children between the ages of five and seven and who have cochlear implants and monolingual, English-speaking only, controls. Children with hearing loss from birth or a very early age who receive a cochlear implant before two to three years of age often have rapidly developing phonological systems with significant changes between five and seven years, which is why understanding the development of their sound systems in this age range is so important.
Currently, clinicians base their treatment decisions for bilingual children with cochlear implants on data from monolingual children or from anecdotal evidence. There is a growing body of research on typically developing bilingual children with normal hearing, and there is also research on monolingual children who use cochlear implants, but research on bilingual children who have cochlear implants is in its infancy.
For children with hearing loss, speech development can be affected by the age at which the child was implanted. Were all of the subjects implanted around the same age? Was that a factor in subject selection?
All of the participants were implanted relatively early, either at or under two years of age. This is an important consideration for our study, because research on children with cochlear implants shows that the age at which a child starts hearing language affects their ultimate oral speech and language attainment. Early implantation has positive effects on later oral language proficiency.
Why did you want to study this particular group of individuals?
Bilingual children with hearing loss who use cochlear implants need appropriate speech and language services, and this research will provide information about their speech development that is critical to designing appropriate diagnostic and therapeutic measures for this population.
Throughout my academic and professional career, I have worked with issues that have the potential to enrich the lives of individuals with various speech, language and hearing disorders. It is my passion. Ultimately, it is about moving the field forward and helping the populations whose speech and language patterns I study.
What are phonological skills? Why are these skills important for the pediatric population and, specifically, bilingual children who use cochlear implants?
Phonological skills relate to the ability to perceive and produce speech in reference to the sound system. Bilingual and monolingual children with and without cochlear implants need to master their phonological systems, because without adequate phonological abilities, both speech and language skills will suffer. Moreover, children with phonological awareness problems may also have literacy problems as they begin to read.
What specialized testing are you developing to evaluate this population adequately? How are the subjects being evaluated?
There are general measures to assess the speech and language skills of monolingual and bilingual children, so we are using some of those to obtain an idea of the performance of our participants relative to their peers with typical development. I have also developed a word list to elicit productions of single words specifically designed to obtain a comprehensive phonological profile of the participants as well as to do some specific measurements of speech. The information gained from our research and the results will provide much needed and valuable data that will help clinicians and educators make decisions that are more informed when it comes to evaluating the speech and language skills of bilingual children with cochlear implants.
You are testing subjects in both their native and second languages. What are the implications for a bilingual child if their native language is not supported or is discouraged?
Michael Douglas, a collaborator from Vanderbilt University, and I are working on projects showing that when the home language is supported by their clinician(s) and caregivers – whether that is English or another language – children perform better. In bilingual children, when the language spoken at home is supported, the overall speech and language skills improve in both languages. A child whose family members speak Spanish at home will benefit from Spanish language support that will improve both their Spanish and their English skills. In fact, children who do not use their home language are less proficient in both of their languages as a result of being deprived of language use at home.
Unfortunately, we think there are children who are deprived of language at home, because they are told not to speak their native language in order to have “less of a language burden.” When they go home, if their parents do not speak English, they do not speak to their children. However, speaking any language at home is better than speaking no or very little language. In a retrospective study that measured the language skills of Spanish-English bilingual children with hearing loss, we found when parents completed assignments at home with their child in their spoken language, the participants performed like monolingual English speaking children with implants. Therefore, if an English only treatment is prescribed, the child may not get the benefit of language support at home. All children, but especially children with hearing loss, need more rather than less language support in order to develop the language skills needed to succeed in life.
What is the significance of this study for not only pediatric cochlear implant users but also the Houston community?
Houston is the fourth largest city in the U.S., and it’s one of the most diverse. According to the latest estimates of the U.S. Census Bureau, 46 percent of the population in Houston speak a language other than English at home. In fact, that number is probably an underestimate of how many people in Houston are bilingual, because some bilinguals choose to speak English at home. Therefore, the research we conduct touches the lives of millions of Houstonians in one way or another.
If we can send a child to the appropriate educational environment as a result of our findings, our study has important implications for the Houston community. Our study has educational impacts and, potentially, an economic impact for taxpayers, because if children are sent to the correct learning environment initially, we could save a lot of money by not having them placed in an inappropriate educational environment for their impairment. That is an advantage for all citizens, particularly for the children who get the appropriate interventions and educational opportunities.
Our engagement with the community is best exemplified by the collaboration we have with Jennifer Wickesberg and the Center for Hearing and Speech in Houston. We recruit and sometimes test participants at the Center for Hearing and Speech in Houston, and I am very grateful for our collaboration. More importantly, this cooperation is not only a perfect example of a symbiotic relationship, but our research will ultimately help the population the Center for Hearing and Speech serves; namely, children with hearing loss who use cochlear implants and hearing aids.
Can you tell me about other projects you are working on currently?
My area of expertise crosses disciplinary lines, so I have collaborations with numerous faculty here at the University of Houston. Dr. Arturo Hernandez (UH Psychology), Dr. Elizabeth Goodin-Mayeda (UH Hispanic Studies), Dr. Pilar Archila-Suerte (UH Psychology) and I are working on collaborative projects involving bilingual and monolingual participants that deal with phonological perception ability, various speech skills and brain activation patterns. We are currently submitting research proposals for funding as well as trying to publish preliminary work on this topic. Recently, I also have started collaborations with Dr. David Francis (UH Psychology), Dr. Kristi Santi (UH College of Education) and Dr. Raúl Rojas (UT Dallas Callier Center) that look at various aspects of speech and language development in bilingual and monolingual school-age children.
The University of Houston has provided me with an environment that both nurtures and challenges me as a researcher and a teacher. I have enjoyed having all the opportunities UH has provided me with, and I am glad I can give back to my University as well as the greater Houston community. It is an honor and a privilege to be a Cougar.
Bunta and Wickesberg are working on this project in collaboration with Michael Douglas, Principal at the Mama Lere Hearing School at the Vanderbilt Bill Wilkerson Center, and Dr. René Gifford, Director of the Cochlear Implant Program at Vanderbilt University, both in the Department of Hearing and Speech Sciences at Vanderbilt University School of Medicine. The research team for this project also includes Rebecca Gonzalez, research speech-language pathologist, Patricia Williams, undergraduate research assistant, Misty Elsby, graduate research assistant, and Daniela Castro, undergraduate research volunteer.
For more information, visit the Department of Communication Sciences and Disorders or the National Institute on Deafness and Other Communication Disorders (NIDCD).