Moberly Aaron C, Lowenstein Joanna H, Nittrouer Susan
Department of Otolaryngology-Head and Neck Surgery, Wexner Medical Center, The Ohio State University, Columbus, Ohio.
Otol Neurotol. 2016 Jun;37(5):470-7. doi: 10.1097/MAO.0000000000001001.
Cochlear implants (CIs) do not automatically restore speech recognition for postlingually deafened adults. Average word recognition remains at 60%, and enormous variability exists. Understanding speech requires knowledge of phonemic codes, the basic sound units of language. Hearing loss may result in degeneration of these long-term mental representations (i.e., "phonemic sensitivity"), and CI use may not adequately restore those representations. This investigation examined whether phonemic sensitivity is degraded for CI users, and whether this degradation results in poorer word recognition.
Thirty adults with CIs and 20 normal-hearing controls underwent testing.
Participants were assessed for word recognition in quiet, along with tasks of phonemic sensitivity using an audiovisual format to maximize recognition: initial consonant choice (ICC), in which they selected the word with the same starting sound as a target word, final consonant choice (FCC), in which they selected the word with the same ending sound, and backwards words, in which they repeated phonemes comprising words in backwards order.
Phonemic sensitivity was poorer for CI users than for normal-hearing controls for ICC and FCC. For CI users, ICC and FCC predicted 25% and 40% of variance in word recognition, respectively. Longer duration of CI use did not lead to greater restoration in phonemic sensitivity.
Even for adults who presumably had developed refined phonemic representations, hearing loss can degrade those representations, which results in poorer word recognition. Cochlear implants do not adequately restore those representations. Findings suggest the need for rehabilitative efforts to improve CI users' phonemic sensitivity.
人工耳蜗（CI）并不能自动恢复语后聋成年人的言语识别能力。平均单词识别率仍为60%，且存在巨大差异。理解言语需要掌握音素代码，即语言的基本语音单位。听力损失可能导致这些长期心理表征（即“音素敏感性”）退化，而使用人工耳蜗可能无法充分恢复这些表征。本研究调查了人工耳蜗使用者的音素敏感性是否退化，以及这种退化是否导致单词识别能力较差。
30名使用人工耳蜗的成年人和20名听力正常的对照者接受了测试。
评估参与者在安静环境中的单词识别能力，以及使用视听形式以最大限度提高识别率的音素敏感性任务：初始辅音选择（ICC），即他们选择与目标单词起始音相同的单词；最终辅音选择（FCC），即他们选择与目标单词结尾音相同的单词；以及倒序单词，即他们按倒序重复构成单词的音素。
在初始辅音选择和最终辅音选择任务中，人工耳蜗使用者的音素敏感性比听力正常的对照者差。对于人工耳蜗使用者，初始辅音选择和最终辅音选择分别预测了单词识别中25%和40%的方差。人工耳蜗使用时间较长并未导致音素敏感性有更大程度的恢复。
即使对于那些可能已经形成精细音素表征的成年人，听力损失也会使这些表征退化，从而导致单词识别能力较差。人工耳蜗不能充分恢复这些表征。研究结果表明需要进行康复训练以提高人工耳蜗使用者的音素敏感性。
