Department of Audiology & Speech Pathology, Bloomsburg University of Pennsylvania, Bloomsburg, Pennsylvania 17815-1301, USA.
J Voice. 2010 May;24(3):285-93. doi: 10.1016/j.jvoice.2008.11.003. Epub 2009 Jun 7.
The purpose of this study was to evaluate the clinical utility of nonlinear dynamic analysis methods, including phase space portraits and measures of the correlation dimension (D(2)) to predict pre- versus post-treatment change in perceived dysphonia severity in a group of 88 patients with muscle tension dysphonia (MTD). Pre- and posttreatment vowel samples from 88 women with primary MTD (mean age=46.2 years; standard deviation=13.1) were selected for analysis (176 voice samples in total). Phase space reconstructions and correlation dimensions were computed to describe the nonlinear dynamic characteristics of all voice samples. Ten blinded listeners were asked to rate the vowel samples for severity of dysphonia using a 100-point visual analog scale (VAS). In the computation of D(2) results, 22 severely dysphonic pretreatment voice samples were not analyzed, as a finite value for the correlation dimension could not be computed. For the remaining pre-/post-treatment voice samples, a significant difference in the correlation dimension (D(2)) between the pre- versus post-treatment voice samples was observed; however, D(2) was poorly correlated with changes in perceived dysphonia severity ratings after treatment (r=0.244, P=0.056). Thus, the utility of the correlation dimension (D(2)) as a treatment-outcome measure and as a measure of dysphonia that may strongly relate to perceived dysphonia severity does not appear to be supported, particularly for pretreatment voices that may have increased levels of dysphonia severity. Instead, the strength of nonlinear dynamic methods may potentially reside in providing some insight into the theoretical rules or initial conditions that may result in different modes of normal or disordered phonation.
本研究旨在评估非线性动态分析方法的临床实用性，包括相空间图和关联维数（D(2)）的度量，以预测 88 例肌紧张性发声障碍（MTD）患者的治疗前后感知发声障碍严重程度的变化。从 88 名患有原发性 MTD 的女性中选择了治疗前和治疗后的元音样本进行分析（总共 176 个语音样本）。为了描述所有语音样本的非线性动态特征，计算了相空间重建和关联维数。10 名盲听测试者使用 100 分视觉模拟量表（VAS）对元音样本的发声障碍严重程度进行评分。在 D(2)结果的计算中，有 22 个治疗前严重发声障碍的语音样本未进行分析，因为无法计算关联维数的有限值。对于剩余的治疗前/后语音样本，观察到治疗前和治疗后语音样本之间的关联维数（D(2)）存在显著差异；然而，D(2)与治疗后感知发声障碍严重程度评分的变化相关性较差（r=0.244，P=0.056）。因此，关联维数（D(2)）作为治疗结果的测量指标以及与感知发声障碍严重程度密切相关的发声障碍的测量指标的实用性似乎并未得到支持，特别是对于可能发声障碍严重程度增加的治疗前语音。相反，非线性动态方法的优势可能在于为不同的正常或紊乱发声模式提供一些理论规则或初始条件的见解。
