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Objectives: This study examined syntactic development of auditory comprehension of sentences in Japanese-speaking school-age children with and without hearing impairment. Methods: In total, 592 preschool and school-age children (421 normal-hearing and 171 hearing-impaired) were included in this cross-sectional observation study conducted using the Syntactic Processing Test for Aphasia for Japanese language users. Linear regression analysis was used to determine the estimated age at which each syntactic structure was acquired. Results: Acquisition of syntactic structures was observed in hearing-impaired and normal-hearing children. Basic word order sentences of agent-object-verb and the goal benefactive construction were acquired at preschool age (earlier group), whereas reverse word order sentences of object-agent-verb, source benefactive construction, passive voice, and relative clauses were acquired at school age (later group). The results showed that many hearing-impaired children may not acquire Japanese grammatical structures until the age of 12 years. Conclusions: Adequate screening for language development for school-age hearing-impaired children is required for an effective intervention.

自由会話における沈黙, 及びミニマル反応の出現と訂正方略の活用について5-8歳の人工内耳装用児 (CI児) 14名と同年齢の聴児11名を比較した。手続きは対象児と検査者の自由会話からスクリプトを作成し, 会話中の沈黙, 及びミニマル反応と訂正方略の活用の出現率を分析した。更に, 背景要因である語音明瞭度, 人工内耳施術年齢, 装用後期間, 言語性知能, 平均発話長との関連性についても検討した。また, 訂正方略の活用数についても比較し, 背景要因との関係も検討した。その結果, CI児は聴児に比べて会話の沈黙, 及びミニマル反応が多く, 特に沈黙が多かった。沈黙, 及びミニマル反応と関係する背景要因は確かめられなかった。訂正方略の活用は, CI児は全体型が多く, 確認型や限定型においては聴児との差は認められなかった。確認型の活用と関係する背景要因は言語性知能であった。

日本音声言語医学会言語委員会の聴覚障害小委員会人工内耳部会は, 1993年に発足し, アンケート調査, ワークショップの開催, 報告書の作成などの活動を行ってきた.本稿では, 人工内耳部会の活動を報告するとともに, 装用者の推移, コード化法の改良, 人工内耳の効果と限界, 適応基準の変化など, 小児人工内耳をめぐる近年の動向を概説した.そして, 今後の課題として, 効果の個人差に及ぼす要因の検討, 健聴児や補聴器装用児との言語発達の比較研究, 評価・訓練法の開発, リハビリテーション・プログラムの整備などがあげられた.とくに, 小児の人工内耳では, 聴取能力だけでなく, 発語能力や言語能力, コミュニケーション能力なども含めた総合的な観点からの検証を行っていくことが重要であることを提言した.

This study was carried out to compare the speech perception ability of patients using hearing aids with hearing levels of 81dB or more (55 patients) and those with cochlear implants (67 patients). The patients with hearing aids were divided into group A (hearing levels 81-90dB, 7 patients), group B (91-100dB, 11 patients), group C (101-110dB, 19 patients), group D (111-120dB, 7 patients), and group E (121-130dB, 6 patients). The patients with cochlear implants were using the strategies of F0F1F2 (14 patients), MPEAK (32 patients) and SPEAK (21 patients). Speech perception tests of monosyllables, words, and sentences under conditions of auditory plus vision were administered. The means and standard deviations of percentages giving the correct answer in F0F1F2, MPEAK and SPEAK were 45.2 +/- 14.7%, 45.7 +/- 14.6% and 62.6 +/- 15.9% for monosyllables, 44.8 +/- 18.9%, 56.3 +/- 15.0% and 73.4 +/- 15.5% for words, and 64.0 +/- 26.4%, 60.5 +/- 15.9% and 84.7 +/- 13.8% for sentences. In comparison with the results for patients with hearing aids, and speech perception for F0F1F2 and MPEAK was equivalent to that of group C, and that for SPEAK was better than that of group B but poorer than that of group A. In other words, the speech perception ability in conventional cochlear implant strategies--F0F1F2 and MPEAK--corresponded to that of patients with hearing levels of 101-110dB, but that in the new strategy, SPEAK, gave better results than 91-100dB.

OBJECTIVES: Speech perception abilities, which vary widely among cochlear implant (CI) users, are considered to be associated with the integrity of the central auditory pathways from the auditory nerve to the cortex. Therefore, auditory evoked potentials (AEPs) are used to evaluate central auditory processing, which is thought to contribute to speech perception in CI subjects. In AEPs, the P300 component reflects the cognitive ability of subjects to detect and respond to stimuli and has most frequently been used and investigated in CI subjects. Other studies have used mismatched negativity (MMN) to examine central auditory processing. It is important to compare MMN and P300 and examine the auditory processing mechanisms involved in these components. Our study therefore aimed to investigate the relationship between P300 and MMN using both active and passive hearing paradigms in CI and normal hearing (NH) subjects. METHODS: Our subjects consisted of 3 CI subjects and 3 NH subjects. An oddball paradigm was used to deliver the stimuli on both components. The frequent stimuli were 1,000-Hz tone bursts, whereas the rare stimuli were 1,500, 2,000, and 4,000-Hz. RESULTS: As the frequency contrasts increased, the P3 latencies increased in the CI subjects. However, the latency in NH subjects did not change significantly across the frequency contrast conditions. MMNs were identified for both the CI and NH subjects; the latencies in the CI subjects were longer than those in the NH subjects. However, there were no differences in the latencies of either the CI or NH subjects in the 3 frequency contrast tasks. CONCLUSION: Our results indicated that different auditory processing pathways are involved in the active and passive hearing conditions based on the P300 and MMN data and that a combination of both responses plays an important role in the comprehension of auditory processing mechanisms in CI subjects.

コクレア社製22チャンネル人工内耳を装用している15名を対象に, リハビリテーション (訓練) 開始後約1, 3, 5, 8, 12週に, 3条件―人工内耳のみ (CI) , 読話のみ (LR) , 人工内耳と読話併用 (CI+LR) ―で文章追唱検査を施行し, 追唱率 (文節/分) の推移および語音認知能検査との関連性・語音認知能検査としての意義について検討した.CI+LR, CIでは訓練経過に伴い上昇する傾向があり, 訓練経過による認知能向上経過を観察できた.訓練開始後約12週での追唱率の平均は, CIで11.9文節/分, LRで4.7文節/分, CI+LRで27.4文節/分であり, 訓練開始後約12週の追唱率と福田版ビデオ教材による語音認知能検査結果との間には, 特にCI+LR, CIに高い相関がみられた.文章追唱検査はその方法を考慮すれば, 人工内耳装用者の訓練経過の観察や簡便な語音認知能の評価法として有効であると示唆された.

多チャンネル型人工内耳装用患者の語音聴取能に影響を及ぼす要因を調べるために, 母音と子音の明瞭度の評価結果と患者の個体要因および電気生理学的要因との関連について統計学的に推定した.個体要因として年齢と失聴期間を, 電気生理学的要因として使用電極数と最小可聴電流値 (Tレベル) , 最大快適電流値 (Cレベル) , TレベルとCレベルの中間値 (平均電流レベル) , TレベルとCレベルとの差 (ダイナミックレンジ) を選定した.単相関分析の結果, 母音の明瞭度と高い相関を示す要因は認められなかったが, 子音の明瞭度と電流刺激域値との間には比較的高い負の相関が認められた.また, 重回帰分析の結果より, 電流刺激域値が低いこと, 使用電極数が多いこと, ダイナミックレンジが広いことの3項目が子音の明瞭度を高める要因の組み合わせであると推定された.

Objectives/Hypothesis: The objective was to clarify the characteristics of deafness associated with the A1555G mutation within mitochondrial 12S ribosomal RNA gene in the absence of aminoglycoside exposure. Study Design: Clinical and genetic studies in family members with the A1555G mitochondrial mutation were performed. Methods: The subjects were 123 maternally related members of a large Japanese family with the A1555G mutation. All subjects had no previous history of exposure to aminoglycosides. Hearing disability and handicap, tinnitus, and medical histories were analyzed by interviews in all of the subjects, genetic testing was performed in 41 subjects, and pure-tone audiometry was conducted in 26 subjects with hearing disability and handicap. Results: The A1555G mutation was detected in a homoplasmic form (meaning that all the mitochondrial DNA carries the mutation) in all 41 subjects who were screened. The risk for developing postlingual hearing loss was likely to be much higher in the present subjects than in the general population. Both the severity and age at onset of the phenotype were similar in affected subjects within the same sibling group. Pure-tone averages were significantly worse in subjects who developed hearing loss before age 10 years than in those who developed hearing loss later. Conclusion: The present study demonstrated that the prevalence of deafness in individuals with the A1555G mitochondrial mutation was likely to be high even in the absence of aminoglycoside exposure and clearly showed the association of severe to profound hearing loss with the onset of hearing loss before age 10 years.

A 6-year-old boy lost his normally-developed language ability within 2 months after bilateral sudden peripheral deafness. The boy became non-communicative with others, restless with frequent meaningless bursts of shouts (communication skills equivalent to 9-11 months of language development: a rapid breakdown of language). Since conservative methods were ineffective, cochlear implantation was performed. A surprising success was observed: he regained the language retracing the normal developmental stages and caught up with his contemporaries in 2 years. Behavioral improvement paralleled his language development. This case (1) provides insights into the brain function with respect to language acquisition, in relation to the plasticity during the 'critical period' of language learning, (2) reveals the close relationship between language development and behavior, and (3) suggests the predominance of auditory stimulation in learning language.

A study was carried out to determine which factors contributed to the vowel and consonant recognition ability of recipients of the 22-channel cochlear implant system. On the basis of the statistical analysis, no isolated factor showed a strong correlation with vowel recognition score. On the other hand, negative correlations were found between patients' consonant recognition scores and postoperative psychophysical percepts such as threshold levels and maximum comfortable loudness levels. However, multiple regression analysis also showed that the combination of lower threshold levels, a larger number of usable electrodes, and wider dynamic ranges contributed to higher consonant recognition scores.

Psychophysical responses of the patients to electrical stimulation were examined in order to clarify long-term effects of the cochlear implant in 9 patients who had received a 22-channel cochlear implant. Measured items were the minimal threshold level (T-level), the maximum comfortable level (C-level), and the dynamic range between T- and C-level. Measurements were repeated for each electrode every three months over more than 6 months. Following results were obtained. 1) The changes of the T-level were classified into four types as follows, a type with no change, a type with gradual decrease, a type with decrease in two to three months followed by gradual increasing threshold and a type with gradual increasing just after surgery. Even in a last type, the maximum increase in the T-level did not exceed 200 microA and, in most cases, these changes were stabilized within a few months after implantation. 2) The dynamic range gradually increased. It was obvious in both in the middle and apical electrodes, while such increased threshold was not observed in the basal electrodes. 3) In some cases, a few basal electrodes could not been used since they caused uncomfortable sensation or those dynamic ranges became below a certain extent. As a result, it was suggested that the electrical stimulation had not induced serious degeneration of the ganglion cells and the auditory nerve fibers. The reduction in the number of usable electrodes might be due to the surgical trauma to the intracochlear tissue. Therefore, exposing of the scala tympani should be minimal in order to avoid the damage of the cochlea.