Overview of Behavioral and Clinical Research at the Boys Town National Research Hospital Nebraska Biomedical Research Retreat 2006

Overview of BTNRH 40,000 outpatients per year. 40,000 outpatients per year. Clinical programs focused on pediatrics and communication disorders. One of the world’s largest communication disorders research programs. Hospital: 1977; Lied Center: 2004; BTNRH - West : 2006

Three Major Areas of Research Clinical and Behavioral Studies of Human Communication Hereditary Communication Disorders Auditory, Vestibular and Retinal Neurobiology For talks this morning, our work in genetics has been subdivided into clinical studies and molecular studies.

Current grant-funded Behavioral and Clinical Research at BTNRH is focused on early identification and remediation of hearing loss. Infant hearing screening Better measurement procedures Communication development Hearing aids and cochlear implants Hereditary communication disorders

Infant Hearing Screening Universal newborn hearing screening is now mandated in Nebraska and most other states. Screening is done using evoked potentials (EPs) and/or oto-acoustic emissions (OAEs). –Normal inner ears produce a faint echo or OAE that can be recorded in the ear canal. –OAEs reflect inner ear mechanics. False positives can be reduced with use of new measures of middle ear function.

Infant Hearing Screening Norms for some EP and OAE measures were developed at BTNRH. Some OAE measurement and screening devices use software developed at BTNRH. 3 BTNRH laboratories are doing research to develop better EP, OAE and middle-ear measurement procedures.

Clinical Sensory Physiology Lab Michael Gorga Goal: To gain greater insight into cochlear processing in both normal and impaired human ears through the use of noninvasive acoustical and electro-physiological techniques. Goal: To gain greater insight into cochlear processing in both normal and impaired human ears through the use of noninvasive acoustical and electro-physiological techniques. Current Projects: –Understanding sources of variability in normal cochlear responses. –Developing more accurate techniques for identifying and quantifying hearing loss in infants, young children, and patients with developmental disabilities. –Determining whether cochlear processing in humans differs for low and high frequencies.

Physical Acoustics Laboratory Douglas Keefe Goal: To better understand: (1) the inter-relationships of the acoustic functioning of the external, middle and inner ear in children and adults, and (2) the impact of this functioning on the processes of hearing in both normal-hearing and hearing-impaired listeners. Goal: To better understand: (1) the inter-relationships of the acoustic functioning of the external, middle and inner ear in children and adults, and (2) the impact of this functioning on the processes of hearing in both normal-hearing and hearing-impaired listeners. Current Projects: –Studies of a new technique to detect middle-ear dysfunction in infants and adults. –Measurement of spectral and temporal processes in human hearing using OAEs. –Use of OAEs to monitor hearing at high frequencies.

Communication Engineering Lab Stephen Neely Goal: Understanding the mechanisms by which the inner ear processes sound information. Goal: Understanding the mechanisms by which the inner ear processes sound information. Current Projects: –Development of mathematical models of cochlear mechanics that provide a correct account of the inner ear’s ability to amplify quiet sounds. –Development of models of auditory perception that take into account the non-linear response of the inner ear. –Development of software to facilitate the measurement and analysis of otoacoustic emissions. –Development of better software to present and record digital audio waveforms.

Better Measurement Procedures Behavioral tests of hearing measure the threshold of hearing (audiogram) or speech perception. Measures of frequency and temporal analysis are not used clinically because they are too variable. Labs working on better measurement procedures include the first 3, plus the Psychoacoustics Laboratory.

Psychoacoustics Laboratory Walt Jesteadt Goal: To understand the rules governing detection and discrimination of simple sounds by human listeners and to use that information to refine models of how the ear processes sounds. Current Projects: –Studies of how subjects make decisions about the sounds they hear in simple intensity resolution tasks. –Studies of how subjects make decisions about the sounds they hear in simple intensity resolution tasks. –We once thought that decisions were based on the amount of energy in specific frequency regions, but we now know that most decisions are more complex.

Communication Development Infant hearing screening is allowing us to identify hearing loss at birth so that we can provide some form of remediation. The goal is to achieve normal communication development. Word learning is an important component of communication development that we can measure. Communication development is obviously closely linked to more general cognitive development.

Infant Development Lab Mary Pat Moeller Goals: –To characterize early word learning strategies of infants with normal and impaired hearing. –To identify perceptual, social-cognitive and linguistic factors influencing word learning. Current Projects –Analysis of maternal responsiveness to words, possible words and other vocalizations. –Study of word learning through overhearing. –Examination of continuity between babble and the first word stage.

Hearing Aids and Cochlear Implants Both technologies rely heavily on digital signal processing. Both require unique procedures when working with infants and young children, including long-term follow-up. Infants with significant hearing loss are fitted with a hearing aid before they are 1-year old. BTNRH is one of the few centers with NIH-funded research programs in both areas. Work is underway in 3 labs.

Hearing Aid Research Laboratory Patricia Stelmachowicz Goal: To explore ways to optimize amplification for infants and young children with hearing loss. Current Projects: –Improved hearing aid signal processing (extended bandwidth, single microphone noise reduction, and frequency compression/transposition). –Structured auditory learning paradigms using high variability training (e.g., multiple talkers) to improve perception in noise or to accelerate the normal course of acclimatization.

Cochlear Implant Research Lab Michelle Hughes Goal: To determine whether physiological measures of implant performance can be used to predict behavioral measures such as judgments of pitch and loudness or speech perception. Current Projects: –Physiological and behavioral measures of channel interaction in cochlear implants. –Clinical outcomes for individuals who were borderline cochlear implant candidates. –Efficacy of bilateral cochlear implants.

Auditory Perception Laboratory Donna Neff Goal: To explore how more central auditory processes such as selective attention affect the ability of adult and child listeners to perceive sounds that are degraded, unpredictable or otherwise non-optimal. Current Projects: –Use of non-speech sounds to determine pattern recognition abilities in children and adults with normal hearing and cochlear implants. –Use of non-speech sounds to determine pattern recognition abilities in children and adults with normal hearing and cochlear implants. –Development of procedures to measure selective auditory attention in children and adults.

Hereditary Communication Disorders At least 50% of the occurrences of childhood hearing loss are genetic in origin. Identification of specific genes provides an entry point for studies of molecular mechanisms. BTNRH was one of the first research centers to localize genes associated with hearing loss. For the past 10 years, most of our research in this area has focused on Usher syndrome, the leading cause of deafness followed by blindness.

Center for the Study and Treatment of Usher Syndrome William Kimberling Goal: To identify novel genes associated with Usher syndrome, develop efficient methods of screening and early diagnosis, and collaborate on clinical trials to determine the effective treatment that would delay or stop the progression of blindness. Current Projects: –Development of state-wide screening programs using chip technology. –Genetic and environmental factors that influence the severity of Usher syndrome. –Identification of novel Usher genes.

Other Areas of Interest Expanded clinical trials in otolaryngology and pediatrics. Boys Town Institute for Child Health Improvement –Directed by Thomas Tonniges, MD –Policy and outcome studies for children and youth with special healthcare needs. Behavioral Health