學齡發展型語言障礙兒童在噪音中的純音時長及語音聽辨

研究目的：本研究目的為探討發展型語言障礙兒童在安靜及噪音情境下對純音時長及語音類別的聽辨表現，用以澄清發展型語言障礙兒童語言能力不佳究竟是肇因於基礎聽知覺處理問題、語音處理困難、或是抑制噪音能力不佳所致。研究方法：研究招募年齡介於10歲至12歲典型發展兒童（控制組）19名及發展型語言障礙兒童（語障組）18名（共計37名）作為研究對象。每位受試者需在安靜與噪音情境中完成AXB形式之純音時長、真字以及假字區辨測驗，並以六項測驗所得之區辨正確率及反應時間作為研究分析之依據。結果：在安靜情境中，語障組的純音時長及假字區辨正確率與控制組沒有差異；語障組的真字區辨正確率則較控制組低，不過兩組兒童的反應時間未有顯著差異。在噪音情境中，語障組的純音時長區辨正確率及反應時間仍與控制組沒有差異；真字及假字區辨正確率皆較控制組低，但兩項測驗的反應時間皆未有顯著差異。另外，本研究亦發現語障組的真字區辨正確率及假字區辨正確率未有顯著差異，但是控制組的真字區辨正確率則優於假字區辨，且兒童的語音區辨正確率與其語言測驗量表的分數有顯著的中度正相關。最後，兩組兒童於安靜情境中的區辨正確率皆高於噪音情境，然而兩組兒童受到噪音影響的程度則未有顯著差異。結論：研究結果顯示發展型語言障礙兒童與典型兒童的表現差距顯現在符合音韻規則的語音信號區辨上，而非是純音信號或是抑制噪音干擾的認知能力，這樣的結果支持語音特定處理缺陷假設，而兒童的語音區辨表現與其語言能力相關，顯示對於符合音韻結構的語音感知與分辨或許才是此類兒童語言能力不佳的因素之一，建議臨床處置能盡早加強語音區辨的訓練，並透過語言相關的介入，增進兒童使用不同語言處理策略以習得語言，進而提升兒童的語言能力。

關鍵字

發展型語言障礙兒童；聽覺區辨；噪音；語音特定

並列摘要

PURPOSE: The purpose of this study was to investigate the auditory performance of children with developmental language disorders on the pure-tone and speech discrimination in quiet and noisy conditions, as to clarify whether the poor language ability of children was caused by basic auditory processing deficit, speech-specific deficit or poor noise suppression ability. RESEARCH METHODS: The study recruited 10 to 12 year-old children, including 19 children who exhibit typical development (TD group) and 18 children with developmental language disorder (DLD group) as research subjects. Each subject was required to complete the pure-tone duration, real words and pseudowords discrimination test in the form of AXB in quiet and noisy conditions, and the accuracy rate and reaction time (RT) were used for research analysis. RESULTS: In the quiet condition, the accuracy rate of pure-tone duration and pseudowords discrimination were no different between TD group and DLD group. The accuracy rate of real words discrimination of DLD group were lower than that in the TD group, but the RT was no different between the two groups. In the noisy condition, the accuracy rate of pure-tone duration discrimination of the DLD group were still no different from that in the TD group. The accuracy rate of real words and pseudowords discrimination of DLD group were lower than those in the TD group, but the RT were still no different between the two group. In addition, this study also found that there was no different between the accuracy rate of real words and pseudowords in the DLD group, but to the TD group, the accuracy rate of real words was higher than pseudowords. Moreover, there was a significant moderate positive correlation with the accuracy rate of phonetic discriminations and the language score. Finally, to the both groups, the accuracy rate in the quiet condition was higher than that in the noisy condition, and the degree of the influence of noise was no significant difference between the two groups. CONCLUSIONS: Research findings suggest that the different discrimination performance between children with developmental language disorder and typically development children, which is manifested in the discrimination of speech signals that is in accord with phonological rules, rather than pure-tone signals or cognitive ability that suppress noise interference, and these results support speech-specific deficit hypothesis. This result indicates that the perception and discrimination of speech, especially which is in accord with the phonological rules may be one of the factors of poor language ability of children with developmental language disorder. It is suggested that intervene the clinical treatment to strengthen children’s speech discrimination ability as soon as possible, and through language-related interventions, help children use different language processing strategies to acquire language, thereby enhancing the language ability of children.