田中 章浩

This study investigated the effects of intermodal timing differences and speed differences on word intelligibility of auditory-visual speech. Words were presented under visual-only, auditory-only, and auditory-visual conditions. Two types of auditory-visual conditions were used: asynchronous and expansion conditions. In the asynchronous conditions, the audio lag was 0-400 ms. In the expansion conditions, the auditory signal was time expanded (0-400 ms), whereas the visual signal was kept at the original speed. Results showed that word intelligibility was higher in the auditory-visual conditions than in the auditory-only condition. The results of auditory-visual benefit revealed that the benefit at the end of words declined as the amount of time expansion increased, although it did not decline in the asynchronous conditions. NeuroReport 20:473-477 (C) 2009 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

This study investigated effects of asynchrony between speech signal and moving image of talker's face induced by time-expansion of the speech signal on speech intelligibility. Word intelligibility test was performed to younger listeners. Japanese 4-mora words were uttered by a female speaker. Each word was processed with STRAIGHT software to expand the speech signal by from 0 to 400 ms. These signals were combined with moving image of talker's face which was kept at original speed. This test was performed under three conditions: visual-only, auditory-only, and auditory-visual (AV) condition. Results showed that intelligibility scores under AV condition were statistically higher than those under auditory-only condition even when the speech signal was expanded by 400 ms. These results suggest that moving image of talker's face is effective to enhance speech intelligibility if the lag between the speech signal and moving image of talker's face does not exceed 400 ms. © OpenInterface Association 2009.

視覚刺激と聴覚刺激が統合されるための呈示タイミング差の許容範囲（時間窓）はおよそ200ms程度であるが，単純な刺激（フラッシュ光と純音）を用いた場合，一定の呈示タイミング差（例：音が200ms遅延）で呈示され続けると，時間窓が拡大する。しかし，この時間窓の補正が，生態学的に妥当性が高く，刺激構造も複雑である音声刺激においても同様に生じるのかは明らかではない。そこで本研究では音声刺激を用い，McGurk効果の生起率を統合の指標とした実験を実施した。実験の結果，音声が233ms遅延するタイミング差に順応した場合，映像と音声が同期するタイミングに順応した場合と比べて，音声が遅延した条件でのMcGurk効果の生起率が上昇した。この結果は音声においても時間窓の補正が機能することを示唆し，視聴覚メディアへの応用が期待できる。

In a mirror, left and right are said to look reversed. Surprisingly, this very familiar phenomenon, mirror reversal, has still no agreed-upon account to date. This study compared a variety of accounts in the light of empirical data. In Experiment 1, 102 students judged whether the mirror image of a person or a character looked reversed or not in 15 settings and also judged the directional relation between its components. In Experiment 2, 52 students made the reversal judgements in 13 settings. It was found for the first time that a substantial proportion of people denied the left-right mirror reversal of a person, whereas virtually all of them did recognize that of a character. This discrepancy strongly suggested that these two kinds of mirror reversal are produced by different processes, respectively. A number of findings including this discrepancy clearly contradicted two accounts that are currently active: the one based on the priority of the up-down and front-back axes over the left-right axis, and the one based on the physical rotation of an object. All the findings were consistent with an account that considered mirror reversal a complex of three different phenomena produced by three different processes, respectively.

人工内耳は一般に音韻の聴取が良くなるように設計・調整されており, 韻律の聴取は必ずしも良くない上, 音韻聴取に干渉する可能性もある。本研究では成人人工内耳装用者 (N24, SPEAK) を対象に単語聴取試験を行い, 1) アクセント型が音韻聴取に与える影響, 2) 音圧が音韻およびアクセント型の聴取に与える影響について検討した。提示音圧は快適レベルの前後に4レベル設定し, 試験単語には2モーラの有意味語に2種類のピッチアクセント (高低型, 低高型) を付与した語を使用した。その結果, 同じ音韻でもアクセント型や音圧の違いによって異なる音韻に異聴する例が認められ, 音韻と韻律の相互作用が示唆された。アクセントの聴取成績は提示音圧で有意差を生じなかったが, 音韻聴取は音圧上昇に伴って向上した。術後の訓練では種々のアクセントや抑揚を含んだ発話を訓練材料に含める必要があることが示唆された。

Previous studies of second language aptitude have mainly used verbal stimuli in memory tasks. Memory for musical stimuli has not been used in aptitude studies although music and language have structural similarity. In this study, 30 Japanese university students who speak English as a second language (19 men, M = 21.3 yr., SD=1.8) participated in the experiment as volunteers. They performed verbal memory tasks, musical memory tasks, and English pronunciation tasks. Factor analysis indicated that verbal and musical memory abilities are better represented as a unitary factor rather than two independent factors. Further, a path analysis supported the hypothesis that the memory for both verbal and musical tasks affects proficiency of second language pronunciation, including prosodic features such as stress in word or intonation through a couple of sentences. The memory factor was interpreted as reflecting the performance of "auditory working memory.".