Although many cochlear implant (CI) users understand speech well in quiet, most of them perform poorly in noisy conditions and in speech intonation and music melody recognition. Dynamic pitch cues are crucial to improve performance in these challenging listening tasks. However, little is known about the mechanisms and factors that contribute to CI users'dynamic pitch perception. In this project, experiments are proposed to investigate and enhance dynamic pitch perception with CI using novel coding strategies. It's hypothesized that optimally combining place and temporal pitch cues within and across frequency channels and using frequency glides to connect discrete tone bursts will lead to better identification of pitch change patterns. The hypotheses will be tested by three experiments with specific aims.
Aim 1 is to assess CI users'pitch contour identification with combined place and temporal pitch cues on individual electrode pairs.
Aim 2 is to assess CI users'pitch contour discrimination interference between a signal and a masker channels.
Aim 3 is to assess CI users'pitch discrimination and melodic contour identification with discrete tone bursts connected by frequency glides. The outcomes of these psychophysical experiments will advance our knowledge on the integration of dynamic pitch cues by CI users, tell us if continuous and discrete pitch changes are differently perceived by CI users, and suggest effective ways to enhance speech intonation, music melody, and noisy speech recognition with CI.
The proposed research will greatly help cochlear implant users face the big challenges of recognizing speech intonations, music melodies, and speech in noise. Improved performance in these tasks will increase the overall quality of life and reverse the social isolation for a large number of cochlear implant users.
|Wu, Ching-Chih; Luo, Xin (2014) Electrode spanning with partial tripolar stimulation mode in cochlear implants. J Assoc Res Otolaryngol 15:1023-36|
|Luo, Xin; Masterson, Megan E; Wu, Ching-Chih (2014) Contour identification with pitch and loudness cues using cochlear implants. J Acoust Soc Am 135:EL8-14|
|Luo, Xin; Chang, Yi-Ping; Lin, Chun-Yi et al. (2014) Contribution of bimodal hearing to lexical tone normalization in Mandarin-speaking cochlear implant users. Hear Res 312:1-8|
|Luo, Xin; Masterson, Megan E; Wu, Ching-Chih (2014) Melodic interval perception by normal-hearing listeners and cochlear implant users. J Acoust Soc Am 136:1831-44|
|Luo, Xin; Ashmore, Krista B (2014) The effect of language experience on perceptual normalization of Mandarin tones and non-speech pitch contours. J Acoust Soc Am 135:3585-93|
|Luo, Xin; Ashmore, Krista B (2014) The effect of context duration on Mandarin listeners' tone normalization. J Acoust Soc Am 136:EL109-15|
|Wu, Ching-Chih; Luo, Xin (2013) Current steering with partial tripolar stimulation mode in cochlear implants. J Assoc Res Otolaryngol 14:213-31|
|Luo, Xin; Padilla, Monica; Landsberger, David M (2012) Pitch contour identification with combined place and temporal cues using cochlear implants. J Acoust Soc Am 131:1325-36|