Research Tops the AAAF's Funding List

The AAA Foundation honors 2005 Research Award recipients at the Celebration Breakfast at Convention 2005: Patrick Feeney and Barbara Packer, AAA Foundation Chair, congratulate (from left) Chul-Hee Choi, Fuh-Cherng Jeng, Bruce Mock and D. Bradley Davis.

The AAA Foundation is pleased to announce the following 2005 Awards for research in the hearing sciences:

2005 Research Awards

Chul-Hee Choi, Ph.D.
New Investigator Award $7,500
The Effect of Perilymph Osmolarity on Cochlear Amplifier

Post Doctoral Research Associate, Baylor College of Medicine, Houston, TX
Mentor: John S. Oghalai, MD, Assistant Professor, Baylor College of Medicine

The long-term goal of this study is to understand how changing biomechanica1 properties of OHC caused by the perilymph osmolarity modulate the cochlear amplifier. The mammalian cochlea is a mechanical structure that is tuned along its length tonotopically. Outer hair cells (OHC) within the cochlea undergo high-speed length changes in response to sound vibrations, generating energy via a positive feedback loop. This is called the cochlear amplifier, and provides exquisite hearing sensitivity and frequency selectivity. OHC motility is based upon the highly organized biomechanica1 structure of the cell's lateral wall, which contains a plasma membrane, a cytoskeleton, and motor proteins. The specific objective of this project is to determine whether osmotic challenge that changes OHC lateral wall biomechanics in vitro will modulate cochlear mechanics in vivo. The compound action potential (CAP), distortion product otoacoustic emissions (DPOAEs), and the basilar membrane velocity will be monitored to assess cochlear function in anesthetized guinea pigs before and after the administration of the artificial perilymph with different osmotic pressures. Additionally, a mathematic model of basilar membrane motion reflecting the unique biophysical nature of the OHC will be improved and modified to well fit the consequences of the experimental manipulations on the biophysical properties on the cochlear tuning.

Kathy R. Vander Werff, Ph.D.
New Investigator Award $10,000
Time and Accuracy of ASSR Response Identification Using Two Different Analysis Methods

Assistant Professor, Syracuse University, Syracuse, NY

The auditory steady-state response (ASSR) is an evoked potential technique that has been shown to provide reliable estimates of behavioral hearing thresholds. Although ASSR has recently become available in commercial equipment and is beginning to be adopted clinically, many questions still remain regarding the best analysis and recording procedures. The goals of this study are to explore some of these questions by evaluating the use of two different ASSR analysis techniques, using Fast Fourier Transform (FFT) or Kalman filtering, using both simultaneous and separate comparisons of the two methods. Specifically, the experiments described in this proposal are designed to (1) directly compare to types of ASSR analysis methods during simultaneous recordings, (2) compare threshold search techniques using these two methods during separate, indecent recordings, and (3) evaluate the clinical utility of stopping criteria for deciding when to terminate averaging for ASSR testing. We hope to determine whether one technique or the other may hold clinical advantages that for objectively estimating hearing thresholds in normal-hearing and hearing-impaired individuals and to investigate useful clinical protocols for recording ASSR.

Lendra Friesen
Student Investigator Award $5,000
Longitudinal Perceptual and Neurophysiologic Changes in CI Listeners

Doctoral Student, University of Washington
Mentor: Kelly Tremblay Ph.D., Associate Professor, University of Washington

Using cortical auditory evoked potentials (NI-P2 complex and P300a evoked potentials) and speech perception measures, we will follow newly implanted post-lingually deafened adults from the time of initial stimulation to 30 days post-hookup. We will quantify and compare experience-related changes in neural activity and speech perception over the 30-day period to determine if there are stimulation-related changes in neural activity over time, and if patterns of neural activity are related to performance (perception) scores. This line of research is motivated from a neuroscience perspective because it provides an opportunity to learn more about brain plasticity as well as the brain-behavior relationship in CI listeners. This research is also motivated from a clinical perspective because we can learn more about the science underlying rehabilitation.

Fuh-Cheng Jeng, M.D.
Student Investigator Award $4,900
Electrically Evoked Auditory Steady-State Responses in Guinea Pigs

University of Iowa
Mentor: Paul J. Abbas Ph.D., University of Iowa
Mentor: Carolyn J. Brown Ph.D., University of Iowa

Auditory steady-state response (ASSR) is an evoked potential that occurs during periodic stimulation. The periodic stimulus is usually a continuous amplitude-modulated sinusoid presented with or without frequency modulation. One potentially useful aspect of the ASSR is that it reflects the response of the auditory system to the envelope of the stimuli, where many important cues of the speech are embedded. Because cochlear implants have becomes widely used all over the world, and because many of the speech processing strategies used in cochlear implants such as CIS (continuous interleaved sampling) used amplitude-modulated stimuli, it would be reasonable to see if it is possible to record the ASSR responses using electrical stimulation, i.e. electrically evoked auditory steady-state responses (ESSR). Preliminary data obtained in our laboratory has shown the feasibility of recording the ESSR using amplitude modulated continuous electric stimuli in guinea pigs. Aim 1 of this project is to assess the feasibility of recording the ESSR by using amplitude modulated pulse trains because pulsatile electric stimuli are more commonly used in cochlear implants. Aim 2 is to characterize the response properties of the ESSR and to use the ESSR to examine the response properties of the auditory system.

Bruce Mock
Student Investigator Award $4,935
Functional Aging of the Inner Ear Sensory Systems

Doctoral Student, East Carolina University
Mentor: Sherri M. Jones, Ph.D. Associate Professor, East Carolina University

The broad, long-term objective of this research is to understand age-related changes in auditory and vestibular sensory modalities in health and disease. We hypothesize that functional aging of one inner ear sensory system does not obligate change in the other and genetic background and/or gender may influence vestibular and auditory aging. Specific aim 1 will characterize age related changes in auditory and vestibular function and will compare changes between the two sensory systems throughout the lifespan in 4 inbred mouse strains with different genetic backgrounds. We will record distortion product otoacoustic emissions (DPOAEs), auditory brainstem responses (ABR), and vestibular evoked potentials (VsEP) at monthly ages from 2 to 18 months. Specific aim 2 will compare inner ear functional aging between males and females. This work will lead to a better understanding of inner ear aging and predisposing factors (genetic and gender) for age related changes in vestibular and auditory function. The work will form the fundamental basis for future studies of anatomical or molecular correlates for inner ear aging and peripheral influences on aging of the central nervous system. Ultimately, the work may lead to better diagnosis and treatment of age related hearing loss and dizziness.

D. Bradley Davis, BA
Summer Research Fellowship $2,500
Automatic Attentional Processes in Aphasia

Louisiana State University Health Science Center
Mentor: Scott Rubin, PhD, Associate Professor, Louisiana State University Health Science Center

The purpose of the proposed research is to return to the original theory that there is some overall attentional difficulty in the soliloquy of aphasia apart from that of linguistic performance. Certain behaviors common in aphasia appear to be related to attention though they may be primarily non-linguistic in nature (i.e., slow-rise time, shutter phenomenon, task perseveration, etc.). In this proposed study, interdisciplinary researchers in Speech-Language Pathology and Audiology will utilize two electrophysiological "oddball" paradigms. One procedure will follow the typical paradigm to elicit the MMN event and the other will seek to illicit P3A, the stage of auditory attention just past the pre-attentive MMN. The P3a event reflects unintentional switching of attention to widely discrepant auditory stimuli. Both these tasks are non-linguistic (non-verbal), and will provide needed information related to the condition of aphasia. Result may refine evaluation and treatment approaches for this common disease.

2005 Student Research Forum

Isabelle Marie Côté, MSc
Award $500
Effect of Noise Reduction Algorithms on Language Acquisition

Ottawa University
Research Advisor: Andre M. Marcoux, Ph.D., University of Ottawa

The reduction in audibility which results from noise reduction

Student Research Forum presenters at Convention 2005 (from left) Brooke Soderstrom, Jennifer Shinn, Isabelle Marie Côté, J. Kip Kelly and Kristin Schroeder.

Jennifer Brooke Shinn, MS
Award $500
ASSR Thresholds in Individuals with Lesions of the CANS

University of Connecticut
Research Advisor: Frank E. Musiek, Ph.D. University of Connecticut

The auditory steady state response (ASSR) has gained attention with respect to estimates of degree of hearing sensitivity and configuration of hearing loss. The purpose of the present investigation was to compare traditional behavioral thresholds to ASSR thresholds in subjects with neurological impairment. Results indicated significant differences between neurological subject's actual behavioral thresholds and ASSR thresholds. This suggests that individuals with neurological insult may present with elevated responses in reference to their behavioral sensitivity.

Brooke Elizabeth Soderstrom, MS
Award $500
The Effect of Masking on the Auditory Steady State Response

University of Connecticut
Research Advisor: Frank E. Musiek, Ph.D. University of Connecticut

The effects of a contralateral broadband masker on Auditory Steady State Response (ASSR) thresholds were investigated in normal hearing adults. A research design was utilized which would closely resemble clinical masking protocols. Findings indicate that the use of a 45dB effective masking stimulus can result in falsely elevated ASSR thresholds. Current implications of this study are important to the clinical application of ASSR as masking procedures are routinely encountered in audiology.

J. Kip Kelly, MS
Award $500
Multitaper Spectral Analysis of ASSR Data

Ohio State University
Research Advisors: Wayne M King, Ph.D., Ohio State Univ.; Lawrence Feth, Ph.D., Ohio State Univ.; Pamela Mishler, Ph.D., Dayton VAMC; Sharon A. Sandridge, Ph.D., Cleveland Clinic Foundation

This study introduces a new set of statistical tests for the detection of ASSRs. ASSR data is collected in the time domain but analyzed in the frequency domain. Current analysis methods suffer from inherent bias and high variability. We propose a novel application of transform techniques shown to alleviate bias and reduce variability. Our data indicate that the improved bias properties and reduced variability of these techniques result in superior detection performance over current methods.

Kristen Schroeder, MA
Award $500
The Effect of Hypothyroidism on Hearing Loss Susceptibility

University at Buffalo
Research Advisor: David A. Eddins, Ph.D., Center for Hearing & Deafness, Univ. at Buffalo

This study examined the effects of hypothyroid state on susceptibility to noise-induced hearing loss (NIHL) in chinchillas. The auditory brainstem response thresholds of thyroidectomized animals were compared to control animals that received a sham surgery. Thresholds were tested pre-surgery, during the post-surgery hypothyroid state, and 3 weeks after exposure to continuous noise. There were no significant differences in post-noise thresholds, suggesting that hypothyroid state neither protects against nor induces NIHL.

2005 James Jerger Awards for Excellence in Student Research

Erin Schafer, MS
Award $500
Developing a Speech Recognition in Noise Test for Children

University of Texas at Dallas
Presenters: Erin C. Schafer, MS, Univ. of Texas at Dallas; Linda Thibodeau, Ph.D., Univ. of Texas at Dallas

The development of a speech recognition in noise test for children, ages 3 to 10, is needed because of the limitations of current materials including vocabulary level, percent-correct scoring, and lack of standardization in noise. The proposed test consists of ten, closed-set phrases presented in an ascending/descending paradigm and classroom noise. Three steps were completed to determine the appropriateness of the vocabulary, equal audibility of the phrases in noise, and reliability of the testing procedure.

Jennifer Shackelford, BA
Award $500
An Adaptive Clinical Test of Temporal Resolution

University of South Florida
Presenters: Jennifer A. Shackelford, BA, Univ. of South Florida; Jennifer J. Lister, Ph.D., Univ. of South Florida; Richard A. Roberts, Ph.D., American Institute of Balance

Broad-band gap detection has been recommended for auditory processing disorder (APD) assessment. Current clinical measures provide results that differ from lab results. The Adaptive Test of Temporal Resolution (ATTR) was developed as a clinical measure that provides results comparable to those obtained in the lab. The ATTR and two other measures were administered to listeners with normal hearing. Results suggest that the ATTR may be a useful addition to the APD test battery.

2005 Association for Research in Otolaryngology Travel Awards

Lendra Friesen
ARO Travel Award $500
Speech Evoked Cortical Potentials as a Function of Cochlear Implant Channel Number

Doctoral Student, University of Washington

Rachael Frush Holt
ARO Travel Award $500
Communication Outcomes as a Function of Age at Cochlear Implantation in Congenitally Deaf Infants and Children: Is Younger Always Better?

NIH Postdoctoral Research Fellow, Indiana University School of Medicine