Comparing bimodal perception skills in infant hearing-aid and cochlear-implant users Brittan A. Barker & J. Bruce Tomblin Department of Otolaryngology— Head & Neck Surgery University of Iowa

Acknowledgements Victoria C. Klein Linda J. Spencer Sandie M. Bass-Ringdahl Courtney M. Burke Michelle L. Hughes The University of Iowa’s Cochlear Implant Team The infants and their families who volunteered their time

research grant 2 P50 DC00242 from the National Institutes on Deafness and Other Communication Disorders, National Institutes of Health. grant RR00059 from the General Clinical Research Centers Program, NCRR, National Institutes of Health. the Iowa Lions Sight and Hearing Foundation. Research supported in part by…

The age at which infants undergo surgery for cochlear implants has considerably declined within recent years. There is a need to systematically collect information regarding hearing-aid and cochlear- implant “benefit” from these infants. Prior research shows that infants with normal hearing have the capabilities to store information about the acoustic signal and begin to learn from it. Background

…to build on the bimodal perception work of Patterson & Werker (2002, 2003) and determine the feasibility of replicating their findings with infants, who use hearing aids and/or cochlear implants. …to determine the point in development at which infants, who use hearing aids and/or cochlear implants, are able to successfully match phonetic information from the lips and voice. Objectives

Design: on-going, longitudinal study that approximates a multiple-baseline design. Participants: 10 infants’ data (3 females) will be presented; infants were assessed at least once prior to cochlear implantation and previous to cochlear implant stimulation. Procedure: The Split-Screen Preferential Looking Procedure (SPLP; Hollich, Hirsh-Pasek, & Golinkoff, 2001) was used to assess bimodal perception skills. Methodology

Stimuli and apparatus /a/ versus /i/ DV camera video monitor experimenter video monitor infant caregiver images appearing on video monitor for infant’s viewing

Experimental design The experiment consisted of two phases, a familiarization phase and a test phase. The familiarization phase was used to introduce the infant to each video in isolation and then in company. No sound was presented. During the succeeding test phase, the same images were presented simultaneously, side-by-side and sound was introduced.

Coding data Each infant’s gaze duration, during the test phase, was summed for each display and averaged across stimulus conditions. This yielded the mean total looking time (in seconds) for each image during the test phase.

Results: individual data, normal hearing thresholds 3-months-old

Results: individual data, cochlear-implant user CI-01 IS = initial stimulation

Results: individual data, cochlear-implant user CI-02 * p <.05

Results: individual data, cochlear-implant user CI-03 * p <.05

Results: group data * n = 10n = 6n = 7n = 3n = 1 p <.05

Exploration of bimodal perception skills in infant, cochlear-implant users is feasible. The cochlear-implant users’ auditory experience via hearing aids was different from the auditory experience via cochlear implants. Individual differences were noted across the participants’ test sessions. Conclusions

Evaluate and compare the differences in audibility and C-levels across children. Compare the emergence of bimodal perception and the emergence canonical babbling. Explore the development of speech perception skills in infants with a variety of hearing levels. Future directions

SPLP Example Experiment: bimodal perception of /a/ & /i/ /i//i//a//a//i//i//a//a/ Familiarization: 6 trials (no sound) with 2s ISI of 9s (2 times) Test phase: 4 trials (sound: counterbalance /a/ AND /i/) with 2s ISI of /i//i//i//i//a//a//a//a/ 27s /a/27s /i/ (2 times) * articulations occur once every 3s, thus 9 artics/trial * sound presented, left-right positioning, and order of familiarization are counterbalanced—yielding 8 conditions