Department of Biology and Function in the Head and Neck, Yokohama City University, Graduate School of Medicine, Yokohama, Japan.
Int J Lang Commun Disord. 2012 Jan-Feb;47(1):84-94. doi: 10.1111/j.1460-6984.2011.00083.x. Epub 2011 Nov 18.
In English- and German-speaking countries, ataxic speech is often described as showing scanning based on acoustic impressions. Although the term 'scanning' is generally considered to represent abnormal speech features including prosodic excess or insufficiency, any precise acoustic analysis of ataxic speech has not been performed in Japanese-speaking patients. This raises the question of what is the most dominant acoustic characteristic of ataxic speech in Japanese subjects, particularly related to the perceptual impression of 'scanning'.
The study was designed to investigate the nature of speech characteristics of Japanese ataxic subjects, particularly 'scanning', by means of acoustic analysis.
METHODS & PROCEDURES: The study comprised 20 Japanese cases with spinocerebellar degeneration diagnosed to have a perceptual impression of scanning by neurologists (ataxic group) and 20 age-matched normal healthy subjects (control group). Recordings of speech samples of Japanese test sentences were obtained from each subject. The recorded and digitized acoustic samples were analysed using 'Acoustic Core-8' (Arcadia Inc.).
OUTCOMES & RESULTS: Sentence duration was significantly longer in the ataxic group as compared with the control group, indicating that the speaking rate was slower in the ataxic subjects. Segment duration remained consistent in both vowels and consonants in the control group as compared with the ataxic group. In particular, the duration of vowel segments, i.e. the nucleus of Japanese mora, was significantly invariable in the control group regardless of differences between subjects as well as in segments compared with the ataxic group. In addition, the duration of phonemically long Japanese vowels was significantly shorter in the ataxic group.
CONCLUSIONS & IMPLICATIONS: The results indicate that the perceptual impression of 'scanning' in Japanese ataxic cases derives mainly from the breakdown of isochrony in terms of difficulty in keeping the length of vowel segments of Japanese invariable during speech production. In addition, the tendency toward irregular shortening of the length of phonemically long Japanese vowels is thought to reinforce the impression of 'scanning' in ataxic speech in Japanese cases.
在英语和德语国家，共济失调性言语通常被描述为基于声学印象的扫描。尽管“扫描”一词通常被认为代表了包括韵律过多或不足在内的异常言语特征，但在讲日语的患者中尚未对共济失调性言语进行任何精确的声学分析。这就提出了一个问题，即在日本受试者中，共济失调性言语最主要的声学特征是什么，特别是与“扫描”的感知印象有关。
本研究旨在通过声学分析探讨日本共济失调性言语的特征，特别是“扫描”。
本研究包括 20 例日本脊髓小脑变性患者，由神经科医生诊断为具有扫描的感知印象（共济失调组）和 20 名年龄匹配的正常健康受试者（对照组）。从每位受试者获得日语测试句子的语音样本录音。使用“Acoustic Core-8”（Arcadia Inc.）对记录和数字化的声学样本进行分析。
与对照组相比，共济失调组的句子持续时间明显更长，表明共济失调组的语速较慢。与对照组相比，在元音和辅音中，音段持续时间保持一致。特别是，日语音节的元音段持续时间，即日本音素的核心，在对照组中无论在受试者之间还是与共济失调组相比，都是非常不变的。此外，在共济失调组中，音长较长的日语元音的持续时间明显更短。
研究结果表明，日语共济失调病例中“扫描”的感知印象主要源于在言语产生过程中保持日语元音段长度不变的同调性的破坏。此外，音长较长的日语元音长度不规则缩短的趋势被认为加强了日语共济失调言语中的“扫描”印象。
