Caldwell Meredith T, Jiradejvong Patpong, Limb Charles J
Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California.
Otol Neurotol. 2016 Mar;37(3):229-34. doi: 10.1097/MAO.0000000000000960.
In light of previous research demonstrating poor pitch perception in cochlear implant (CI) users, we hypothesized that the presence of consonant versus dissonant chord accompaniment in real-world musical stimuli would not impact subjective assessment of degree of pleasantness in CI users.
Consonance/dissonance are perceptual features of harmony resulting from pitch relationships between simultaneously presented musical notes. Generally, consonant sounds are perceived as pleasant and dissonant ones as unpleasant. CI users exhibit impairments in pitch perception, making music listening difficult and often unenjoyable. To our knowledge, consonance/dissonance perception has not been studied in the CI population.
Twelve novel melodies were created for this study. By altering the harmonic structures of the accompanying chords, we created three permutations of varying dissonance for each melody (36 stimuli in all). Ten CI users and 12 NH listeners provided Likert scale ratings from -5 (very unpleasant) to +5 (very pleasant) for each of the stimuli.
A two-way ANOVA showed main effects for Dissonance Level and Subject Type as well as a two-way interaction between the two. Pairwise comparisons indicated that NH stimuli pleasantness ratings decreased with increasing dissonance, whereas CI ratings did not. NH pleasantness ratings were consistently lower than CI ratings.
For CI users, consonant versus dissonant chord accompaniment had no significant impact on whether a melody was considered pleasant or unpleasant. This finding may be partially responsible for the decreased enjoyment of many CI users during music perception and is another manifestation of impaired pitch perception in CI users.
鉴于先前的研究表明人工耳蜗（CI）使用者的音高感知能力较差，我们推测在现实世界的音乐刺激中，协和与不协和和弦伴奏的存在不会影响CI使用者对愉悦程度的主观评价。
协和/不协和是由同时呈现的音符之间的音高关系所产生的和声感知特征。一般来说，协和音听起来令人愉悦，不协和音则令人不悦。CI使用者在音高感知方面存在障碍，这使得他们在听音乐时感到困难且往往无法享受其中。据我们所知，尚未在CI人群中研究过协和/不协和感知。
为该研究创作了12首新颖的旋律。通过改变伴奏和弦的和声结构，我们为每首旋律创建了三种不同不协和程度的排列组合（总共36种刺激）。10名CI使用者和12名正常听力（NH）的听众对每种刺激给出从-5（非常不悦）到+5（非常愉悦）的李克特量表评分。
双向方差分析显示了不协和程度和受试者类型的主效应以及两者之间的双向交互作用。成对比较表明，NH组的刺激愉悦度评分随着不协和程度的增加而降低，而CI组则不然。NH组的愉悦度评分始终低于CI组。
对于CI使用者而言，协和与不协和和弦伴奏对旋律是否被认为愉悦或不悦没有显著影响。这一发现可能部分解释了许多CI使用者在音乐感知过程中愉悦感降低的原因，也是CI使用者音高感知受损的另一种表现。
