Browsing by Author "Maarefvand, Mohammad"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    A bilateral cochlear implant user with exceptional musical hearing ability
    (Informa Healthcare, 2013-06) Maarefvand, Mohammad; Marozeau, Jeremy; Blamey, Peter
    Although the perception of music is generally poor in cochlear implant users, there are a few excellent performers. Objective: The aim of this study was the assessment of different aspects of music perception in one exceptional cochlear implant user. Design: The assessments included pitch direction discrimination, melody and timbre recognition, relative and absolute pitch judgment and consonance rating of musical notes presented through the sound processor(s). Study sample: An adult cochlear implant user with musical background who lost her hearing postlingually, and five normally hearing listeners with musical training participated in the study. Results: The CI user discriminated pitch direction for sounds differing by one semitone and recognized melody with nearly 100% accuracy. Her results in timbre recognition were better than average published data for cochlear implant users. Her consonance rating, and relative and absolute pitch perception were comparable to normal hearing listeners with musical training. Conclusion: The results in this study are an “existence proof” that excellent performance is possible on musical perception tasks including pitch perception using present day cochlear implant technologies. Factors that may explain this user’s exceptional performance are short duration of deafness, pre and post deafness musical training and perfect pitch abilities before the onset of deafness.
  • Thumbnail Image
    Item
    Pitch matching in bimodal cochlear implant patients: Effects of frequency, spectral envelope, and level
    (Acoustical Society of America, 2017-11) Maarefvand, Mohammad; Blamey, Peter; Marozeau, Jeremy
    This study systematically investigated the effects of frequency, level, and spectral envelope on pitch matching in twelve bimodal cochlear implant (CI) users. The participants were asked to vary the frequency and level of a pure or complex tone (adjustable sounds) presented in the nonimplanted ear to match the pitch and loudness of different reference stimuli presented to the implanted ear. Three reference sounds were used: single electrode pulse trains, pure tones, and piano notes. The data showed a significant effect of the frequency and complexity of the reference sounds. No significant effect of the level of the reference sounds was found. The magnitude of effect of frequency was compressed in the implanted ear: on average a difference of seven semitones in the non-implanted ear induced the same pitch change as a difference of 19 to 24 semitones for a stimulus presented to the implanted ear. The spectral envelope of the adjustable sound presented to the non-implanted ear also had a significant effect. The matched frequencies were higher by an average of six semitones for the pure tone compared to a complex tone. Overall, the CI listeners might have matched the stimuli based on timbre characteristics such as brightness.