Skinner M W, Holden L K, Holden T A, Demorest M E, Fourakis M S
Department of Otolaryngology-Head & Neck Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA.
J Acoust Soc Am. 1997 Jun;101(6):3766-82. doi: 10.1121/1.418383.
Ten postlinguistically deaf adults who used the Nucleus Cochlear Implant System and SPEAK speech coding strategy responded to vowels, consonants, words, and sentences presented sound-only at 70, 60, and 50 dB sound-pressure level. Highest group mean scores were at a raised-to-loud level of 70 dB for consonants (73%), words (44%), and sentences (87%); the highest score for vowels (70%) was at a conversational level of 60 dB. Lowest group mean scores were at a soft level of 50 dB for vowels (56%), consonants (47%), words (10%), and sentences (29%); all except subject 7 had some open-set speech recognition at this level. For the conversational level (60 dB), group mean scores for sentences and words were 72% and 29%, respectively. With this performance and sound-pressure level, it was observed that these subjects communicated successfully in a variety of listening situations. Given these subjects' speech recognition scores at 60 dB and the fact that 70 dB does not simulate the vocal effort used in everyday speaking situations, it is suggested that cochlear implant candidates and implantees be evaluated with speech tests presented at 60 dB instead of the customary 70 dB sound-pressure level to simulate benefit provided by implants in everyday life. Analysis of individuals' scores at the three levels for the four speech materials revealed different patterns of speech recognition among subjects (e.g., subjects 1 and 5). Future research on the relation between stimuli, sound processing, and subjects' responses associated with these different patterns may provide guidelines to select parameter values with which to map incoming sound onto an individual's electrical dynamic range between threshold and maximum acceptable loudness level to improve speech recognition.
十名使用核人工耳蜗系统和SPEAK语音编码策略的语后聋成年人，对仅以70分贝、60分贝和50分贝声压级呈现的元音、辅音、单词和句子做出反应。辅音（73%）、单词（44%）和句子（87%）的最高组平均得分出现在70分贝的提高响度水平；元音的最高得分（70%）出现在60分贝的会话水平。元音（56%）、辅音（47%）、单词（10%）和句子（29%）的最低组平均得分出现在50分贝的柔和水平；除受试者7外，所有受试者在此水平都有一定程度的开放式言语识别。在会话水平（60分贝）下，句子和单词的组平均得分分别为72%和29%。基于这样的表现和声压级，观察到这些受试者在各种听力情况下都能成功交流。鉴于这些受试者在60分贝时的言语识别得分，以及70分贝不能模拟日常说话情况下的发声努力这一事实，建议对人工耳蜗候选者和植入者进行评估时，采用60分贝而非常规的70分贝声压级呈现言语测试，以模拟植入物在日常生活中提供的益处。对四种言语材料在三个水平上的个体得分分析显示，受试者之间存在不同的言语识别模式（例如，受试者1和5）。未来关于刺激、声音处理与这些不同模式相关的受试者反应之间关系的研究，可能会为选择参数值提供指导，以便将传入声音映射到个体在阈值和最大可接受响度水平之间的电动态范围内，从而提高言语识别能力。
