Skinner M W, Fourakis M S, Holden T A, Holden L K, Demorest M E
Department of Otolaryngology-Head & Neck Surgery, Washington University School of Medicine, St. Louis, Missouri, USA.
Ear Hear. 1996 Jun;17(3):182-97. doi: 10.1097/00003446-199606000-00002.
The main objective was to evaluate differences in performance associated with the two speech coding strategies. To achieve this objective, acoustic and electrical analyses of vowels identified by cochlear implant recipients were compared with their responses when they used the Multipeak (MPEAK) and the Spectral Peak (SPEAK) speech coding strategies of the Nucleus Cochlear Implant System.
Nine subjects identified pure and r-colored English vowels with the two speech coding strategies. The two processing strategies were compared using an ABAB design. Evaluations were conducted at two weekly sessions after at least 3 wk of use with each strategy.
Group vowel identification scores with the MPEAK versus the SPEAK strategy were not significantly different (72.3% and 73.4%, respectively). However, hierarchical loglinear analysis of group data showed that transmitted information of r-color, duration, and second-formant features was significantly better with the SPEAK than with the MPEAK strategy. In contrast, identification of the first formant feature was significantly better with the MPEAK than with the SPEAK strategy. Individual subjects had different error patterns in response to the 14 vowels.
Electrical stimulation with the SPEAK strategy provides clearer spectral representation of second formant and duration information as well as second and third formant change in r-colored vowels than with the MPEAK strategy. Consequently, there was marked improvement in recognition of r-colored vowels with SPEAK compared with MPEAK. In contrast, transmitted information for first-formant features was significantly less with SPEAK than with MPEAK. This may have occurred because four instead of six to eight electrodes were assigned to first formant frequencies with SPEAK versus MPEAK.
主要目的是评估与两种言语编码策略相关的性能差异。为实现这一目标，将人工耳蜗植入者识别出的元音的声学和电分析结果，与他们使用核人工耳蜗系统的多峰（MPEAK）和频谱峰（SPEAK）言语编码策略时的反应进行了比较。
9名受试者使用两种言语编码策略识别纯英语元音和r色彩元音。采用ABAB设计对两种处理策略进行比较。在每种策略至少使用3周后的两个每周一次的疗程中进行评估。
MPEAK策略与SPEAK策略的组元音识别分数无显著差异（分别为72.3%和73.4%）。然而，对组数据的分层对数线性分析表明，与MPEAK策略相比，SPEAK策略在r色彩、时长和第二共振峰特征的传输信息方面显著更好。相比之下，MPEAK策略在第一共振峰特征的识别方面比SPEAK策略显著更好。个体受试者对14个元音的反应有不同的错误模式。
与MPEAK策略相比，SPEAK策略的电刺激在r色彩元音中能提供更清晰的第二共振峰和时长信息的频谱表示，以及第二和第三共振峰变化。因此，与MPEAK相比，使用SPEAK时r色彩元音的识别有显著改善。相比之下，SPEAK在第一共振峰特征的传输信息方面比MPEAK显著更少。这可能是因为与MPEAK相比，SPEAK将四个而非六到八个电极分配给了第一共振峰频率。
