1) Sequential Learning in Children with Cochlear Implants (American Speech and Hearing Foundation Clinical Research Grant; PI: Elizabeth A. Walker):
In this study, we test the hypothesis that auditory deprivation prior to cochlear implantation leads to delays in domain-general learning processes. To investigate this topic, we use dynamic learning tasks that assess children’s ability to learn non-linguistic visual and motor patterns. These paradigms will allow us to determine whether there is an association between grammar abilities and learning in verbal, visual, and motor contexts. The specific aims of this project include 1) evaluating performance on a sequential non-verbal learning task in children with cochlear implants, and 2) evaluating performance on a motor learning task in children with cochlear implants. The outcomes of this study will provide empirical evidence regarding neurocognitive and learning processes in children with cochlear implants. Understanding these processes will lead to the development of effective interventions for children with hearing loss. This study is funded by the American Speech, Language, Hearing Foundation.
2) Outcomes of School-Age Children who are Hard of Hearing (NIH/NIDCD R01 DC009560, PIs: J. Bruce Tomblin and Mary Pat Moeller):
Although children with mild-to-severe hearing loss compose the majority of children with hearing loss, most research has focused primarily on children with severe-to-profound hearing losses. The small number of studies on children who are hard of hearing suggest that they are at risk for delays in language and academic achievement. However, most studies related to children who are hard of hearing were conducted prior to the implementation of universal newborn hearing screening. There is a critical need to examine the outcomes of a new generation of early-identified children with access to current amplification systems. The Outcomes of School-Age Children who are Hard of Hearing (OSACHH) project is a longitudinal study conducted by investigators representing three primary sites: the University of Iowa, Boys Town National Research Hospital, and the University of North Carolina-Chapel Hill. In this project, we examine how early intervention and children’s preschool communication abilities influence school-age academic and literacy outcomes. The results of this project have important implications for determining risk and protective factors for children with mild-to-severe hearing loss.
In children with normal hearing, early narrative skills predict later academic success. Little is known, however, about the narrative skills of children with mild-to-severe hearing loss. In this study, we posed the following research questions: 1) is hearing status related to narrative production scores? and 2) what factors influence spontaneous and retell narrative scores in children who are hard of hearing? We examined the association between narrative scores and various audiologic, linguistic, and cognitive factors. This project has helped to identify specific malleable factors, such as aided audibility, that appear to support higher-level language skills in children who are hard of hearing.
Home and School Remote Microphone Use:
There is clear evidence that children who are hard of hearing need a better signal-to-noise ratio (SNR) to understand speech in complex listening situations compared to their hearing peers. Remote microphone (RM) systems increase SNR, which leads to improvements in speech perception. In this project, we had two goals: 1) to provide insight into how RM systems are being used by preschool-age children who are hard of hearing at home and at preschool, and 2) to compare language outcomes of preschool-age children who are hard of hearing with and without RM systems at home. We also examined factors that influence RM receipt. The results of this study have important implications for early intervention in children who are hard of hearing.
3) Complex Listening (NIH/NIDCD R01 DC013591; PI: Ryan W. McCreery):
Complex Listening in School-Age Hard of Hearing Children is a longitudinal study funded by the National Institute for Deafness and Other Communication Disorders. It is a collaborative project with researchers from Boys Town National Research Hospital and the University of Iowa. We posit that early language and cognitive abilities form the foundation for listening and learning in classrooms during elementary school. Children who are hard of hearing who have deficits in these skills may face significant academic and social challenges as they enter school. The long-term goal of the Complex Listening project is to optimize amplification and speech understanding in children who are hard of hearing by identifying the underlying processes that support listening in academic and social situations. We strive to understand how inconsistent auditory experience during early childhood affects speech understanding in noise and reverberation and on complex tasks that require cognitive processing. Results of this study will inform scientific theories about the developmental consequences of inconsistent early auditory experience. Clinically, the results will guide evidence-based practice and health policy for the clinical management of children who are hard of hearing.
Children who are hard of hearing have inconsistent access to the speech signal, which impairs the bottom-up process of decoding speech. Without receiving the entire speech stimulus, large cognitive demands are placed on higher-level processes that facilitate language comprehension, namely cognitive functioning and linguistic knowledge. In this study, we used a gating task to investigate how bottom-up and top-down processes affect speech recognition in children with hearing aids. In a gating task, the child must guess the last word of a sentence when varying amounts of the end of the word have been removed. We addressed the following questions: 1) Do children who are hard of hearing require more acoustic information on a gated speech recognition task than children with normal hearing? 2) Do children who are hard of hearing use sentence predictability to facilitate performance? and 3) Do the linguistic and cognitive skills of children who are hard of hearing influence the amount of acoustic information needed for speech recognition? The results of this project have important clinical implications regarding the importance of providing contextual information when speaking with children with or without a hearing loss.