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Speech perception tests are commonly used as indices reflecting hearing ability in daily life. In Japan, the CI-2004 test, first developed in 2004, is widely used as standard, but it was not validated against a large number of normal hearing controls and hearing loss patients. The primary objective of the present study was to develop and validate iPad-based software for the Japanese monosyllable speech perception test, ‘iCI2004’. Seven universities and two medical centers participated in this study. The hearing threshold and Japanese monosyllable speech perception test results of 77 people with normal hearing and 459 people with hearing loss were collected. All participants with normal hearing achieved almost perfect perception results both in quiet and in noise. For cochlear implant users, the average monosyllable speech perception score was 55.1 ± 19.6% in quiet and 40.3 ± 19.2% in noise (SNR + 10dB). We developed iPad-based Japanese monosyllable speech perception test software and validated it by testing a large number of controls and hearing loss patients with cochlear implants or hearing aids. The developed monosyllable speech perception test has a sufficiently large dynamic range for assessing improvement in speech perception in Japanese cochlear implant users.

Bilateral Cochlear implants (CIs) improved speech intelligibility, speech perception in background noise, and sound localization in quiet and noisy situations. However, it is unclear whether these advantages essentially result in binaural integration of acoustic stimuli from each ear. In this study, we investigated the effectiveness of binaural integration by bilateral CIs placement using binaural hearing tests and subjective auditory perceptual assessment. A 61-year-old bilateral CIs subject underwent the following four tests: the Japanese Hearing in Noise Test (HINT-J), the dichotic listening test (DLT), the Rapidly Alternating Speech Perception (RASP) test, and subjective auditory perceptual assessment. The HINT-J score was significantly higher for bilateral CIs than for a unilateral CI. However, DLT and the RASP test revealed contradictory results. Subjective auditory perceptual assessment revealed active and bright impressions for bilateral hearing, which were also noisy and strong compared with those for unilateral hearing. The results of this study revealed that bilateral CIs improved speech perception in background noise and an improved auditory impression, although the bilateral integration abilities were not improved. This was probably because the patient was required to combine information from the two ears into a single perception in DLT and the RASP test. More longitudinal data should be collected and analyzed in future studies to evaluate the long-term effects of bilateral CIs.

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。

To elucidate the pathophysiological and genetic mechanisms of hearing loss associated with the homoplasmic mitochondrial A1555G mutation in the absence of aminoglycoside exposure, we conducted audiological and genetic analyses on 67 maternally related members of a large Japanese family carrying this mutation. A consistent pattern was evident in the audiograms, with features of sensory presbycusis, cochlear origin at all levels of hearing loss, and a high degree of vulnerability of outer hair cells. That the degree of hearing loss was similar in affected subjects within the same sibling group but differed between sibling groups suggests the involvement of nuclear modifier genes. Total mitochondrial DNA sequences were completely identical among subjects with various levels of hearing loss, and lacked additional pathogenic mutations. For the diagnosis of sensorineural hearing loss, the mitochondrial A1555G mutation should be considered when these features are present even in the absence of aminoglycoside exposure.

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.

人工内耳装用成人65名, 小児8名の語音知覚検査結果に基づき, 言語臨床の観点から聴覚機能の再学習や可塑性, および聴覚情報の処理メカニズムについてRetrospectiveに検討した.人工内耳装用による語音の知覚率は個人差が著しく, その個体要因として, 失聴時期と失聴期間が関与することが示唆された.一般に失聴時期が早く失聴期間が長いと言語知覚率は劣化する傾向にあったが, 長期間の失聴でも聴覚の再学習は可能であることが示唆された.ところが, 小児は, 先天性でも3歳前後の手術症例はオープンセットの語音知覚が可能になり, 幼児の脳の可塑性の高さが示唆された.言語習得期での失聴児は, 失聴期間が2年以内の症例は聴覚機能の再学習が早かった.なお, 聴覚情報の音声処理機構については, 成人はトップダウンの概念処理が主であった.小児はボトムアップ処理が先行し, 言語獲得に伴いトップダウン処理併用がみられた.

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.

The aim of this study is to investigate the perception mechanism of environmental sounds in postlingual patients with cochlear implants compared with that in patients with central auditory disorders. Seventeen postlingual patients with cochlear implants were studied; six patients with auditory nerve disease (auditory neuropathy) and ten patients with cortical deafness were selected for the comparison. A taperecorded environmental sound perception test of 24 environmental sounds was carried out. This test is divided into two categories: the category of voice includes human voice, animal and bird sounds, and the category of non-voice includes musical instrument sound, natural sound and artificial sound. The percentage of correct perception of environmental sounds in postlingually deaf patients with cochlear implants was markedly higher than that in patients with cortical deafness, but was similar to that in patients with auditory nerve disease (auditory neuropathy).

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.

In the cochlear implant, change in voice pitch is transmitted through the periodicity of change in density of neural pulse trains excited by the electrical signal. As the transmission quality of the voice pitch depends on the setting of the processor of each device, it is necessary to measure precisely the discrimination ability of change in voice pitch for each user, and to make maximum use of it. For this purpose, a CAI (Computer Assisted Instruction) system for testing and training the discrimination was developed.

The Japanese Hearing in Noise Test (JHINT) was developed following the step of the Enlish version (Nilsson et al., 1994), and this report summarizes the procedures used in JHINT.A total of 1000 dai...

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.

Aiming at the maximum use of linguistic information conveyed by the periodicity pitch of speech sound through cochlear implants, the possibility of improving the voice pitch discrimination threshold was examined for cochlear implantees: three acquired deaf adults and four congenitally deaf children. Female and male adult speech samples of vowel /a/ were analyzed and resynthesized using the STRAIGHT computer program to shift the original voice pitch (c1 and c) one octave upward and downward with a half‐step interval on the musical scale. By presenting those synthetic speech samples in pairs, the discrimination threshold of the voice pitch interval was observed. Association of the speech samples to the picture of a piano keyboard was helpful for conceptualizing the voice pitch change, especially for children. Preliminary observation results suggested that the discrimination threshold can be improved by less than one whole step by adults and two whole steps by children. Those figures were promising because, ...

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.