Development of auditory attention in children

The ability to attend selectively to objects in the environment follows a well-documented developmental course through the pre-school and school-aged years. Some aspects of selective attention are not fully developed until late in the teens. Current research focuses on the development of the ability of children to understand what is spoken by a target talker in a background of other talkers or noise. Results to date suggest that preschool and young school-aged children are especially susceptible to interference from distracting talkers and that there are large individual differences in resistance to distraction. The hope is that a better understanding of the factors that contribute to this interference will lead to the development of learning environments to minimize it.

Recent Publications:

Oh, E. L., Wightman, F., & Lutfi, R. A. (2001). Children's detection of pure-tone signals with random multitone maskers. The Journal of the Acoustical Society of America, 109(6), 2888-2895.

Wightman, F. L., Callahan, M. R., Lutfi, R. A., Kistler, D. J., & Oh, E. (2003). Children's detection of pure-tone signals: informational masking with contralateral maskers. The Journal of the Acoustical Society of America, 113(6), 3297-3305.

Wightman, F. L., & Kistler, D. J. (2005). Informational masking of speech in children: effects of ipsilateral and contralateral distracters. The Journal of the Acoustical Society of America, 118, 3164-3176.

Auditory attention in children and adults who use cochlear implants

The cochlear implant is rapidly becoming the treatment of choice for children and adults who are deaf. However, although many deaf individuals derive tremendous benefit from cochlear implant use, many others do not. The goal of the research on people who use cochlear implants is to understand the source of this individual variability, with the eventual aim of maximizing the benefit of an implant for all those who receive one. The implant provides the auditory system with an electrical representation of the acoustical world that is crude compared to what is provided by a fully-functioning cochlea. Thus, selectively attending to a desired source in a noisy environment presents special challenges to implant users. Current research examines the impact of the degraded auditory input on auditory selective attention abilities, with a special emphasis on children. This research is new, but to date it appears that successful users of a cochlear implant, especially children implanted before the age of two years, suffer relatively little from the degraded auditory input and attend in much the same way as individuals with normal hearing.

Use of visual cues to aid auditory attention Ð A/V integration

The ability to attend to a target talker in a noisy environment is facilitated, in many cases, by being able to see the target talker. This Auditory/Visual (A/V) integration of cues is likely to be extremely important to a hearing-impaired or deaf individual who uses a hearing aid or a cochlear implant. The research on A/V integration aims to understand how it develops, in both normally hearing children and in children who use a cochlear implant. In addition, we hope to learn how the benefit of added visual cues depends on the ability of a listener to lipread. Preliminary evidence suggests that in normally hearing children, even the ability to lipread does not always lead to a large A/V benefit, suggesting the involvement of other, still-developing cognitive skills.

Recent publications:

Wightman, F. L., & Kistler, D. J. (2006). Informational masking of speech in children: audiovisual integration. Journal of the Acoustical Society of America, 119, 3940-3949.

Use of spatial cues to aid auditory attention

In adults with normal hearing, auditory selective attention is facilitated when the target sound is spatially separated from the distracting sounds. This is known as the "cocktail party effect", and has been the subject of a large number of research studies over the past decade. Research on this phenomenon seeks to understand how spatial separation might benefit auditory selective attention in children and in individuals who use a cochlear implant. There is an obvious intuitive relationship between the benefit of spatial separation of target and distracter and the ability to localize the two sources. Thus, one might expect that children, who do not appear to localize as well as adults, would not gain as much benefit as adults with spatial separation. In addition, individuals who us a single cochlear implant are notoriously poor at localizing sounds, and thus might be expected to obtain no benefit at all from spatial separation of target and distracter sounds. Preliminary results suggest that both of these predictions are supported. However, when individuals who use a cochlear implant are outfitted with a special in-the-ear microphone that captures the acoustical cues provided by pinna diffraction, there is some benefit of spatial separation.

VOLUNTEER OPPORTUNITIES

All of the research programs conducted in the Wightman-Kistler laboratory depend on volunteer participants to serve as "listeners". These individuals are recruited from the UofL student population, the adjacent Louisville Deaf Oral School, and the surrounding community. All projects involving volunteer participants follow informed consent procedures approved by the UofL Human Subjects Protection Program (IRB). For more information on which projects need volunteer listeners, contact Dr. Doris Kistler, at doris.kistler@louisville.edu, or 502-852-3862.

STAFF:

Dr. Fred Wightman, Ph. D.
Dr. Doris Kistler, Ph. D.
Scott Stauble, Graduate Assistant