Department of
Auditory Implants and Perception (DAIP)
Speech Technology and Hearing Research
Mission Statement
- To understand the mechanisms involved in speech pattern recognition by the electrically stimulated auditory system, and further, the plasticity of the auditory cortex.
- To develop assessment and training strategies that maximize speech recognition in adults and children fitted with a cochlear implant or a hearing aid.
- To provide innovative speech software to people with hearing problems based on the state-of-art speech technology and recent research findings in cochlear implants, hearing aid, speech and hearing science, language development, and auditory plasticity. Please visit TigerSpeech Technology for more information.
Research
NIDCD R01 DC04792: Effects of Training on Adult Cochlear Implant Users
Summary: The long-term goal of the proposed study is to develop assessment and training strategies that maximize speech recognition in adults and children fitted with a cochlear implant (Cl). This study will focus on adult Cl users with lower than average (poor) speech recognition skills. It will capitalize on the benefits of a combined behavioral and neurophysiological approach to characterize psychophysical and speech recognition skills and construct individualized training strategies. The hypothesis of this study is that the discrimination abilities of simple and complex stimuli can be improved by intensive training. Therefore, we predict that a Cl user with poor speech recognition can significantly benefit from intensive psychophysical and speech training. We further hypothesize that neurophysiological measures of central auditory system activity [e.g., the mismatch negativity (MMN) and P3a], can be used to first assess potential discrimination abilities prior to training, then guide and monitor the effects of training.
NIDCD R01 DC04993: Speech Pattern Recognition in Electric Hearing
Summary: The long-term goal of this research is to understand the mechanisms involved in speech pattern recognition by the electrically stimulated auditory system, and further, the plasticity of the auditory cortex. The present proposal will address three fundamental questions of speech perception in electric hearing: 1) How are the electrically evoked peripheral neural patterns of speech affected by parametric variations of the speech processor? 2) How are the central speech pattern templates reshaped by new peripheral neural patterns? 3) What are the causes of the high variability in speech performance among cochlear implant patients? The hypothesis of this research is that speech recognition in electric hearing is primarily based on a similarity measure between electrically evoked peripheral neural discharge patterns and central speech pattern templates. Based on patients’ experience with the implant device, central speech pattern templates can accommodate new peripheral neural patterns, to some degree. We further hypothesize that a deficit in auditory resolution (temporal and/or spectral) can remarkably reduce cochlear implant users’ capabilities in speech pattern recognition. The high variability of speech performance among cochlear implant users is largely due to a deficit in the auditory resolution of the individual patient, as well as the mismatch between the peripheral neural patterns and central speech pattern templates.
Research and Commercial Products
Research Staff
Qian-Jie Fu, Ph.D.
Scientist II
Section Chief, Speech Technology and Hearing Research, HEI
Research Associate Professor, Department of Biomedical Engineering, USC
John J. Galvin
Senior Research Associate
Xiaosong Wang, MSCE, MPH
Software Engineer
Geri Nogaki,
Research Associate
Xin Luo, Ph.D.
Post-doc Scientist
Chuping Liu, Ph.D. Student
(EE, University of Southern California)
Yi-Ping Chang, Ph.D. Student
(BME, University of Southern California)
Tianhao Li, Ph.D. Student
(BME, University of Southern California)
Sherol Chinchilla, Graduate Student
(Speech and Hearing, California State University)
