Audiology and Speech Pathology, University of Tennessee, Knoxville, TN 37996, USA.
Int J Lang Commun Disord. 2009 Nov-Dec;44(6):1000-17. doi: 10.1080/13682820802546951.
Stuttering is prone to strike during speech initiation more so than at any other point in an utterance. The use of auditory feedback (AAF) has been found to produce robust decreases in the stuttering frequency by creating an electronic rendition of choral speech (i.e., speaking in unison). However, AAF requires users to self-initiate speech before it can go into effect and, therefore, it might not be as helpful as true choral speech during speech initiation.
To examine how AAF and choral speech differentially enhance fluency during speech initiation and in subsequent portions of utterances.
METHODS & PROCEDURES: Ten participants who stuttered read passages without altered feedback (NAF), under four AAF conditions and under a true choral speech condition. Each condition was blocked into ten 10 s trials separated by 5 s intervals so each trial required 'cold' speech initiation. In the first analysis, comparisons of stuttering frequencies were made across conditions. A second, finer grain analysis involved examining stuttering frequencies on the initial syllable, the subsequent four syllables produced and the five syllables produced immediately after the midpoint of each trial.
OUTCOMES & RESULTS: On average, AAF reduced stuttering by approximately 68% relative to the NAF condition. Stuttering frequencies on the initial syllables were considerably higher than on the other syllables analysed (0.45 and 0.34 for NAF and AAF conditions, respectively). After the first syllable was produced, stuttering frequencies dropped precipitously and remained stable. However, this drop in stuttering frequency was significantly greater (approximately 84%) in the AAF conditions than in the NAF condition (approximately 66%) with frequencies on the last nine syllables analysed averaging 0.15 and 0.05 for NAF and AAF conditions, respectively. In the true choral speech condition, stuttering was virtually (approximately 98%) eliminated across all utterances and all syllable positions.
CONCLUSIONS & IMPLICATIONS: Altered auditory feedback effectively inhibits stuttering immediately after speech has been initiated. However, unlike a true choral signal, which is exogenously initiated and offers the most complete fluency enhancement, AAF requires speech to be initiated by the user and 'fed back' before it can directly inhibit stuttering. It is suggested that AAF can be a viable clinical option for those who stutter and should often be used in combination with therapeutic techniques, particularly those that aid speech initiation. The substantially higher rate of stuttering occurring on initiation supports a hypothesis that overt stuttering events help 'release' and 'inhibit' central stuttering blocks. This perspective is examined in the context of internal models and mirror neurons.
口吃者在开始说话时比在话语的其他任何一点更容易出现口吃。已经发现，使用听觉反馈（AAF）通过创建合唱语音的电子副本（即，齐声说话），可以显著降低口吃的频率。然而，AAF 要求用户在其生效之前自行发起语音，因此，它在语音启动期间可能不如真正的合唱语音有用。
研究 AAF 和合唱语音如何在语音启动和随后的话语部分中不同地增强流畅性。
十名口吃者在没有改变反馈的情况下（NAF）阅读短文，然后在四种 AAF 条件和一种真正的合唱语音条件下阅读。每个条件分为十个 10 秒的试验，每个试验之间间隔 5 秒，因此每个试验都需要“冷”语音启动。在第一次分析中，比较了不同条件下的口吃频率。第二次更精细的分析涉及检查初始音节、后续四个音节和每个试验中点后立即产生的五个音节的口吃频率。
平均而言，AAF 将口吃频率相对于 NAF 条件降低了约 68%。初始音节的口吃频率明显高于其他分析的音节（NAF 和 AAF 条件分别为 0.45 和 0.34）。在第一个音节产生后，口吃频率急剧下降并保持稳定。然而，与 NAF 条件（约 66%）相比，AAF 条件下的口吃频率下降幅度显著更大（约 84%），分析的最后九个音节的平均频率分别为 NAF 和 AAF 条件的 0.15 和 0.05。在真正的合唱语音条件下，整个话语和所有音节位置的口吃几乎（约 98%）消除。
改变的听觉反馈在语音启动后立即有效地抑制口吃。然而，与外源性启动并提供最完整流畅性增强的真正合唱信号不同，AAF 需要用户发起语音并“反馈”才能直接抑制口吃。因此，AAF 可以成为口吃者的一种可行的临床选择，并且通常应与治疗技术结合使用，特别是那些有助于语音启动的技术。在启动时发生的口吃率明显更高，支持了一个假设，即明显的口吃事件有助于“释放”和“抑制”中枢性口吃障碍。这一观点在内部模型和镜像神经元的背景下进行了探讨。
