Production and discrimination of voicing contrast of stops in cases of phonological disorder

The voicing contrast of stops represents a complex acoustic and articulatory coordination, frequently impaired in cases of phonological disorders. Consequently, we believe that the efforts should be carried out in order to understand the factors that influence in the stabilization of that contrast. So, the purpose of this research was correlating the production data and the performance in a discrimination test of the feature [+voice] in children with phonological disorder. Then, five boys who presented phonological disorder, difficulties in the production of voiced stops and other difficulties, were evaluated. Through the pairs of words introduced in carrier phrases, we observed the occurrence of production of positive Voice Onset Time during the [+voice] stops and the duration pattern of the vowels adjacent to the voiced and voiceless stops. The authors elaborated a Stop Voicing Discrimination Test to evaluate the performance of the individuals regarding to the discrimination. The test consists of 12 pairs of words, being only different in the contrast [+voice] and it is represented by pictures. Through a descriptive analysis, no direct relation between difficulties of the production of voicing contrast of stops and auditory discrimination of this sounds was verified, both on the observation of prevoicing production, regarding the pattern production observation of the length of the vowel. Nevertheless, we emphasize that the use of a discrimination test, as well as of acoustical analysis in cases of phonological disorder, should not be ignored by the speech therapist, once those instruments can give important information to a good therapeutic progress.

塞音的嗓音对立是一种复杂的声学与发音协调机制，在语音障碍（phonological disorder）患者中常出现受损情况。据此，我们认为应开展相关研究以明确影响该对立机制稳定的各类因素。本研究旨在探究语音障碍儿童的塞音[+嗓音]特征的发音数据与辨别测试表现之间的相关性。本研究共评估了5名存在语音障碍、浊塞音发音困难及其他相关言语问题的男性儿童。通过载体句中呈现的词汇对，我们分别观测了[+嗓音]塞音的正嗓音起始时间（Voice Onset Time, VOT）产生情况，以及浊塞音与清塞音相邻元音的时长模式。研究者自行编制了塞音嗓音辨别测试（Stop Voicing Discrimination Test）以评估受试者的辨别能力：该测试包含12组词汇对，仅在[+嗓音]对立维度上存在差异，并以图片形式呈现。通过描述性分析，无论是针对预发声发音的观测，还是针对元音时长模式的产生表现观测，均未发现塞音嗓音对立的发音困难与该类语音的听觉辨别能力之间存在直接关联。不过需强调的是，言语治疗师不应忽视使用辨别测试与声学分析手段辅助语音障碍患者的诊疗，此类工具可为优化治疗效果提供关键参考信息。