Cochlear implant characteristics for CI participant inclusion and vocoder creation.

<p>Cochlear implant characteristics for CI participant inclusion and vocoder creation.</p

Experience Changes How Emotion in Music Is Judged: Evidence from Children Listening with Bilateral Cochlear Implants, Bimodal Devices, and Normal Hearing

<div><p>Children using unilateral cochlear implants abnormally rely on tempo rather than mode cues to distinguish whether a musical piece is happy or sad. This led us to question how this judgment is affected by the type of experience in early auditory development. We hypothesized that judgments of the emotional content of music would vary by the type and duration of access to sound in early life due to deafness, altered perception of musical cues through new ways of using auditory prostheses bilaterally, and formal music training during childhood. Seventy-five participants completed the Montreal Emotion Identification Test. Thirty-three had normal hearing (aged 6.6 to 40.0 years) and 42 children had hearing loss and used bilateral auditory prostheses (31 bilaterally implanted and 11 unilaterally implanted with contralateral hearing aid use). Reaction time and accuracy were measured. Accurate judgment of emotion in music was achieved across ages and musical experience. Musical training accentuated the reliance on mode cues which developed with age in the normal hearing group. Degrading pitch cues through cochlear implant-mediated hearing induced greater reliance on tempo cues, but mode cues grew in salience when at least partial acoustic information was available through some residual hearing in the contralateral ear. Finally, when pitch cues were experimentally distorted to represent cochlear implant hearing, individuals with normal hearing (including those with musical training) switched to an abnormal dependence on tempo cues. The data indicate that, in a western culture, access to acoustic hearing in early life promotes a preference for mode rather than tempo cues which is enhanced by musical training. The challenge to these preferred strategies during cochlear implant hearing (simulated and real), regardless of musical training, suggests that access to pitch cues for children with hearing loss must be improved by preservation of residual hearing and improvements in cochlear implant technology.</p></div

Normal hearing subjects attempt to use mode cues whenever possible.

<p>Percentage change in opinion (top) and change in reaction time (bottom) in response to cue changes for normal hearing subjects (NH) listening to degraded conditions compared to unilateral CI children (CI) listening in quiet: children with normal hearing performed similarly to unilateral CI users in both the vocoder 32 (dark gray) and vocoder 22 (black) conditions across cue change conditions, but also in the pink noise condition (light gray) only when tempo cues were changed. They still performed similarly in the pink noise and quiet (white) conditions when mode cues were changed independently or in conjunction with tempo cues. Error bars indicate standard error. * p<0.05, *** p<0.001.</p

Emotion identification under different pitch-degraded conditions in normal hearing subjects.

<p>Mean accuracy (top) and reaction time (bottom) for the original version of normal hearing subjects under different acutely degraded acoustic input conditions, compared to those of a group of unilaterally implanted CI children in quiet (right white bar): accuracy in the pink noise (light gray), vocoder 32 (dark gray) and vocoder 22 (black) conditions were significantly less than in quiet (white), with pink noise generating the worst performance and the longest reaction time. Error bars indicate standard error. * p<0.05, *** p<0.001.</p

Demographic information for participants in Experiment 1.

<p>* mean age in years ± standard deviation (range)</p><p>Demographic information for participants in Experiment 1.</p

Role of duration and type of hearing experience in CI patients' emotion identification skills.

<p>(A) Percentage change in opinion when cues are changed across duration and type of hearing experience in bilateral CI users (plus signs) versus bimodal users (circles): hearing experience rather than absolute age seems to be the most important factor for developing emotion identification in music. Some of the main associations are as follows: length of hearing deprivation did not affect emotion identification skills; the longer children used CI(s), the less they were affected by changes in mode cues and the more they relied on tempo; children with greater acoustic sound experience (bimodal users) were less affected by tempo cues than the bilateral CI users; age at first implantation and age at test did not affect overall performance. (B) Percentage change in opinion when cues were changed across hearing level and pure tone thresholds in bilateral CI users (plus signed) versus bimodal users (circles): children with a greater degree of low frequency hearing loss and overall hearing loss were more affected by tempo cues (ie. relied more on tempo than on mode cues). Only associations that reach a trend level (p<0.1) or significance (p<0.05) are shown.</p

Accurate emotion identification is achieved across ages and musical experience.

<p>Mean accuracy (top) and reaction time (bottom) for the original version of the MEI test for children (white bar) and adults (grey bar) with normal hearing: both children and adults achieved similar accuracy and reaction times for distinguishing happy from sad melodies. Error bars indicate standard error.</p

Musical training enhances use of distorted mode cues.

<p>Percentage change in opinion when cues are changed across years of formal musical training and experimental conditions in musicians: music experience did not affect reliance on tempo, even with a pitch-deprived signal, while specific training progressively affected emotion identification skills when pitch cues were present. When little-to-no pitch information was provided, length of musical training had no bearing on opinion changes with mode changes. Only associations that reach a trend level (p<0.1) or significance (p<0.05) are shown.</p

Age and musical training affect emotion identification skills.

<p>(A) Percentage change in opinion (top) and reaction time (bottom) for children (white bar) and adults with normal hearing (grey bar) when mode and tempo cues were changed: tempo changes affected opinion the least while combined cue changes affected opinion the most, though children were more affected by tempo changes than adults. (B) Effects of years of musical training in both children and adults: musicians changed their opinions 4.7% more, 1.6% less and 4.5% more with each extra year of musical training when mode, tempo or both cues were changed, respectively. Error bars indicate standard error. ** p<0.01, *** p<0.001, only associations and interactions that reach a trend level (p<0.1) or significance (p<0.05) are shown.</p