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Language Development Lab


The overall goal of our research program is to examine the outcomes of early-identified children who are deaf and hard of hearing and identify factors that explain performance differences among these children. Within longitudinal and cross-sectional research designs, we compare speech, language, and social-cognitive development outcomes of children with typical hearing to those of children who are deaf and hard of hearing. These studies focus on early identification of children who are at risk for delays, and on finding improved methods for preventing and/or ameliorating delays.


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 can 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. This area is equipped with monitors, recording devices, and computers for PC-based data collection and analysis. Transcript preparation and coding is accomplished with Systematic Analysis of Language Transcripts (SALT) and Child Language Analysis (CLAN) software. The Language Development Laboratory is located in the Lied Learning and Technology Center at Boys Town National Research Hospital, a separate child-friendly facility adjacent to the Hospital building. A laboratory in close proximity houses a double-walled sound-attenuated booth suite for hearing assessments. A hearing-aid analysis/probe-microphone system (Audioscan Verifit) is available to quantify real-ear gain as a function of frequency on an individual basis. The laboratory also houses a set of LENA (Language ENvironment Analysis) devices and associated software applications. 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, is a researcher with combined expertise in audiology and child language. Her program of study has focused on speech, language, and social-cognitive outcomes in children who are deaf and hard of hearing.

Internal Collaborators

Sophie E. Ambrose, Ph.D, Ryan McCreery,Ph.D., Pat Stlemachowicz, Ph.D. Merry Spratford, Au.D., Lauren Berry, M.S., Colleen Fitzgerald, M.A., Ashley Halbach, Au.D., Barbara Peterson, MHD, Susan Nutty, M.S.

External Collaborators

J. Bruce Tomblin, Ph.D. University of Iowa and the Outcomes of Children with Hearing Loss (OCHL) research team:
See -
Amanda Owen Van Horne, Ph.D., University of Iowa and
Mark VanDam, Ph.D., Washington State University

Summary of Research Program

For Clinicians and Scientists

Current studies are focused on understanding the outcomes of children who are hard of hearing (Pure tone averages of 25-75 dB HL). Our laboratory is working in collaboration with the University of Iowa and the University of North Carolina at Chapel Hill to conduct a longitudinal, multidisciplinary study of the outcomes of newly identified, hard-of-hearing (HH) children. The Outcomes of Children with Hearing Loss (OCHL) team is following over 300 HH children across 17 states, compared to 115 children with typical hearing, who are matched on age and socioeconomic status. The NIDCD estimates that 30,000 children in the U.S. under the age of 6 are hard of hearing. Most of these children are provided with audiological and early childhood education services. However, there has been very limited research regarding the developmental outcomes of these children or the effectiveness of the services provided. Our study is designed to answer these gaps in our knowledge about the speech and language outcomes of children who are hard of hearing.

A summary of our current OCHL research findings may be found at:

We will continue to follow this cohort over the next five years to determine how preschool status influences the development of language and literacy in the school-age years. This new phase of the work is entitled Outcomes of School-​Age Children with Hearing Loss (OSACHH).

Previous research in the Language Development Laboratory focused on characterizing the vocabulary growth and associated word learning processes in infants and young children with typical hearing and those who were deaf or hard of hearing. We examined 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 continue to examine qualitative and quantitative aspects of maternal talk across the groups. Our ongoing 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 children with normal hearing. This work gives us insights about ways to improve hearing aids and ways to guide families in stimulating optimal auditory and spoken language development.

To learn more about our current work, visit

See a video about our study:

Research Study Participation

If you are interested in participating in a Research Study with the Boys Town National Research Hospital, please click here fill out the a registration form.​

Selected Publications (DVD resources)

Selected Publications

Moeller, M.P. (2000). Early intervention and language development in children who are deaf and hard of hearing. Pediatrics. 106(3), e43-51.

Stelmachowicz, P.G., Pittman, A.L., Hoover, B.M., Lewis, D.C., & Moeller, M.P. (2004). The importance of high-frequency audibility in the speech and language development of children with hearing loss. Archives of Otolaryngology. Head and Neck Surgery. 130(5), 556-562.

Moeller, M.P. & Schick, B.S. (2006). Relations between maternal input and theory-of-mind understanding in deaf children. Child Development. 77(3), 751-766.

Moeller, M.P., Hoover, B., Putman, C., Arbataitis, K., Bohnenkamp, G., Peterson, B., Wood, S.L., Lewis, D.E., Pittman, A.L., & Stelmachowicz, P.G. (2007a). Vocalizations of infants with hearing loss compared to infants with normal hearing--Part I: Phonetic development. Ear and Hearing, 28(5), 605-627.

Moeller, M.P., Hoover, B., Putman, C., Arbataitis, K., Bohnenkamp, G., Peterson, B., Estee, S., Lewis, D.E., Pittman, A.L., & Stelmachowicz, P.G. (2007b). Vocalizations of infants with and without hearing loss--Part II: Transition to words. Ear and Hearing 28(5), 628-642.

Moeller, M.P. (2007). Current state of the knowledge: Psychosocial development in children with hearing impairment. Ear and Hearing, 28(6), 729-739.

Moeller, M.P., Tomblin, J.B., Yoshinaga-Itano, C., Connor, C.M. & Jerger, S. (2007). Current state of knowledge: Language and literacy of children with hearing impairment. Ear and Hearing 28(6), 740-753.

Moeller, M.P., Hoover, B., Peterson, B. & Stelmachowicz, P.G. (2009). Consistency of hearing aid use in infants with early-identified hearing loss. American Journal of Audiology, 18, 14-23. (PMCID: PMC2692469).

Moeller, M.P. (2009, July 14). Hearing aid use by infants: More than meets the ear? The ASHA Leader, 14(9), 28.

Moeller, M.P., McCleary, E., Putman, C., Tyler-Krings, A., Hoover, B. & Stelmachowicz, P. (2010). Longitudinal development of phonology and morphology in children with late-identified mild-moderate sensorineural hearing loss. Ear and Hearing. 31(5), 625-635. (PMCID: PMC - In Process).

VanDam, M., Ide-Helvie, D. & Moeller, M.P. (2011). Point vowel duration in preschoolers with hearing loss at four and five years of age. Clinical Linguistics and Phonetics, 25(8), 689-704.

Moeller, M.P., Bass-Ringdahl, S., Ambrose, S.E., VanDam, M., & Tomblin, J.B. (2011). Understanding communication outcomes: New tools and insights. In R. C. Seewald & J. M. Bamford (Eds.), A Sound foundation through early amplification: Proceedings of the 2010 international conference (pp. 245-260). Phonak AG Immediate Proceedings Ltd., Stafa, Switzerland. [Public Access Compliance - N/A, Book Chapter]

Koehlinger, K., Van Horne, A., & Moeller, M. P. (in press). Grammatical outcomes of 3 & 6 year old children with mild to severe hearing loss. Journal of Speech-Language-Hearing Research.

Holte, L., Walker, E., Oleson, J. J., Spratford, M., Moeller, M. P., Roush, P., . . . Tomblin, J. B. (2012). Factors influencing follow-up to newborn hearing screening for infants who are hard of hearing. American Journal of Audiology, 21(2), 163-174. doi:10.1044/1059-0889(2012/12-0016)

Walker, E., Spratford, M., Moeller, M. P., Oleson, J. J., Ou, H., Roush, P. A., & Jacobs, S. (2013). Predictors of hearing aid use time in children with mild-severe hearing loss. Language, Speech, and Hearing Services in Schools, 44, 73-88. doi: 10.1044/0161-1461(2012/12-0005)

​​VanDam, M., Ambrose, S. E., & Moeller, M. P. (2012). Quantity of parental language in the home environments of hard-of-hearing 2-year-olds. Journal of Deaf Studies and Deaf Education, 17(4), 402-420. doi:10.1093/deafed/ens025