Research in this laboratory explores the development of selected aspects of child language (phonology, word learning, morpho-syntax, theory of mind) in normal-hearing and hard-of-hearing infants. In particular, we work in collaboration with the Hearing Aid Research Laboratory (directed by Dr. Pat Stelmachowicz) at Boys Town National Research Hospital to understand the impact of variables such as auditory experience, audibility and access to the speech signal on the rate and quality of young children’s language learning. Previous projects have included longitudinal evaluation of the effects of FM system use on language learning, study of factors that influence long-term language outcomes in early and late-identified children with hearing loss, and investigation of the influence of mother-child conversations on theory of mind development in deaf children. One of the current projects examines the phonological composition of babble and first words in normal hearing and hard of hearing infants. Because of newborn hearing screening, hard-of-hearing infants are being identified early in life, providing the opportunity to carefully document developmental stages of speech and language learning from their inception. This work is providing insights about limitations of traditional amplification strategies and may lead to improvements in auditory interventions for hard of hearing infants. The newest area of investigation in the laboratory explores factors that influence early novel word learning strategies in normal hearing and hard-of-hearing infants. These studies will assist us in designing preventative interventions to facilitate word learning in young children with hearing loss.
The laboratory consists of a large playroom, designed to foster natural parent-child interaction, and an adjoining experimenter observation/analysis room. The playroom is equipped with 2 Panasonic Professional DVCPRO AJ-D610 digital video cameras, mounted on pan heads that may be controlled by remote from the observation room. Two Telex wireless lavaliere microphones are used for audio recordings. An infrared intercom system allows for communication between the playroom and the observation area. The observation/analysis area is equipped with a professional Sony 21” color monitor that includes time code generation on the screen during data collection sessions. This area has three IBM desktop computers, one of which has a DVD writer. Two stations are used for data analysis and include Transana, CHAT and SALT transcript analysis software. The third computer station is devoted to compression of digitized video samples. The laboratory also has a Dell notebook computer, used for presentation of digital movies during data collection. The Infant Development Laboratory is located in the new Lied Learning and Technology Center at Boys Town National Research Hospital, a separate child-friendly facility adjacent to the Hospital building. The Lied Center includes state-of-the-art digital video facilities, an editing studio, and both a wireless and hard-wired network for PCs and laptops.
Mary Pat Moeller, Ph.D, directs the laboratory. Barbara Peterson is responsible for the day-to-day operation of the laboratory. Pat Stelmachowicz, Ph.D. is a co-investigator on the longitudinal projects, with particular interest in the effects of auditory experience on phonological and lexical learning. Research assistants include speech pathologists, Coille Putman, Katie Arbitatis and Andrea Parsons.
Summary of Research Program
For Clinicians and Scientists
The research program focuses on longitudinal and cross sectional experiments designed to characterize the time course of vocabulary and associated word learning processes in infants and young children with normal and impaired hearing. We are examining the degree of continuity between the phonetic compositions of babble and early words in these two groups of children. Through longitudinal analysis of mother-child interaction, we are examining qualitative and quantitative aspects of maternal talk across the groups, including mother’s early input about internal states. Another major goal in the laboratory is to understand the impact of incidental learning (overhearing) on vocabulary acquisition and novel word learning in normal hearing and hard of hearing infants. Furthermore, we are working to determine if hard-of-hearing children, like normal hearing children, use cues from speaker intention and speaker knowledge states as a strategy for learning novel words. Our investigations include longitudinal analysis of maternal input related to internal states and children’s growing social understanding.
Newborn hearing screening has opened new doors for families who have infants with hearing loss. In the past, young hard of hearing children were not identified until two years of age or later. By this point, these children had missed early auditory experiences that helped them develop the foundations of language and speech. Newborn hearing screening puts us in a position of providing these children early access to sound and an opportunity to prevent major delays in speech and language. However, we still have much to learn in order to accomplish this goal. Because hard-of-hearing children have only recently been identified early in life, we do not have many research studies examining their early development. Our early studies suggest that it is not enough just to put hearing aids on infants. Rather, they require specialized help to learn language at a typical rate. The work in our lab is designed to gain an understanding of the unique learning and listening needs of infants with hearing loss. We do this by carefully comparing their development to infants with normal hearing. This gives us insights about ways to improve hearing aids and ways to guide families in stimulating optimal auditory and spoken language development. Some of our experiments look at the strategies young children use to learn new words. We hope to make discoveries that will shape the ways we promote vocabulary development in hard of hearing infants.
Specific Areas of Research:
- Phonological development in normal hearing and hard-of-hearing infants
- Influence of auditory access and auditory experience on morphological learning in hard-of-hearing infants
- Influence of maternal input on lexical learning strategies
- Characterizing learning rates and strategies for word learning in normal hearing and hard of hearing infants
- Relationships between mother-child-sibling talk about internal states and the development of false belief understanding in normal hearing and hard-of-hearing children
- Impact of access to overhearing on novel word learning