聽障學童送氣與不送氣語詞清晰度研究

Intelligibility of Aspirated and Unaspirated Words by Hearing-impaired Students

本研究主要在於探討啟聰班聽覺障礙學童送氣與否語詞的清晰度，分別從聽知覺的評量和聲學分析二方面，分析聽障兒童的語詞清晰度表現。以自編「送氣與不送氣語詞」詞卡、「送氣與否語詞清晰度評量表」、「送氣與否語詞清晰度評分表」、及Dr. Speech & Real Speech語音分析軟體為研究工具，以八十八學年度台南市忠義國小六十名聽力正常中、高年級兒童，及台南縣市啟聰班中、高年級聽障學童二十二名為對象，探究聽障學童送氣與不送氣語詞的聽知覺清晰度、相關背景因素與語詞清晰度的關聯、聽常與聽障學童送氣與不送氣語詞噪音起始時間聲學特質、聽障學童構音錯誤類型等，期以研究結果提供聽障學童語音分析研究參考模式，及聽能說話訓練參考訊息。本研究結果主要發現如下：一、聽障學童送氣與不送氣語詞聽知覺清晰度聽障學童送氣語詞的聽知覺清晰度平均為58.90％，不送氣語詞的聽知覺清晰度平均為58.88％。二、相關背景因素與聽障學童送氣與不送氣語詞清晰度的關聯啟聰班聽障學童中，女性學童的清晰度優於男性學童；年齡與年級低者清晰度比年齡、年級大者佳；在聽力損失方面，大部份聽障學童（72.7％）的聽閾值在90dB以上，聽閾值愈低者清晰度愈佳；助聽系統方面，聽障學童大多配戴助聽器（81.8％），所配戴助聽器型式全部為耳掛型，亦有人工電子耳（13.6％）及只在上課才戴FM助聽系統者（4.5％），人工電子耳聽障學童比配戴助器聽障學童清晰度佳。三、聽常學童送氣與不送氣語詞的噪音起始時間聽常學童各送氣語詞的噪音起始時間（平均111.73亳秒）皆比不送氣與語詞（平均41.22亳秒）長，送氣語詞與不送氣語詞之噪音起始時間未重壘，且兩者之間達統計上.001顯著差異水準，可做為區分送氣與否的依據；另外噪音起始時間顯示可區分塞音與塞擦音的不同及語音之不同構音部位。四、比較聽障學童與聽常學童送氣與不送氣語詞嗓音起始時間的差異聽障學童之送氣與否語詞噪音起始時間表現比聽常學童短，且分散性極大，無法有效區分出語音送氣與否，不同語段塞音與塞擦音的差別，塞擦音噪音起始時間比塞音長的特質，及構音部位不同之語音等。五、聽障學童語詞構音錯誤類型聽障學童所呈現的語詞構音錯誤類型有以下五種：（一）母音化；（二）鼻音化；（三）吐氣音；（四）詞界不分明；（五）送氣時間不足。

This study is aimed to investigate the intelligibility of aspirated and unaspirated words spoken by hearing-impaired students in special classes. Perception assessment and acoustic analysis are used to explain the word intelligibility of hearing-impaired children. My 'aspirated and unaspirated word cards', 'assessment form of intelligibility of aspirated and unaspirated words', 'evaluation form of intelligibility of aspirated and unaspirated words', and Dr Speech & Real Speech sound analysis software are the research tools used to investigate the perceptive intelligibility of aspirated and unaspirated words by hearing-impaired students, relationship between relevant background factors and word intelligibility, acoustic characteristics about voice onset time of aspirated and unaspirated words by normal students and hearing-impaired students, and types of sound-producing mistakes by hearing-impaired students, etc. And it is hoped that the research results can be provided as reference mode and material in the analysis and research of words by hearing-impaired students and their hearing and speech training. The main findings of this study are as follows:1. Perceptive intelligibility of aspirated and unaspirated words by hearing-impaired students. The perceptive intelligibility of aspirated words by hearing-impaired students is 58.90% on average, and their perceptive intelligibility of unaspirated words is averaged 58.88%.2. Relationship between relevant background factors and intelligibility of aspirated and unaspirated words by hearing-impaired students. Female hearing-impaired students have a better intelligibility than male hearing-impaired students. Students who are younger or at lower grades have a better intelligibility than those who are older or at higher grades. Regarding the hearing loss, the hearing threshold value of most hearing-impaired students (72.7%) is above 90dB. The lower the hearing threshold value is, the better the intelligibility will be. As to the hearing-aid system, most hearing-impaired students wear the hearing aids (81.8%), and all are the behind-the-ear type. There are also the cochlear implant (13.6%) and the FM system used only in class (4.5%). The hearing-impaired students using the cochlear implant have a better intelligibility than the ones wearing hearing aids.3. Voice onset time of aspirated and unaspirated words by normal students. The voice onset time of each aspirated word by normal students (111.73 ms on average) is always longer than that of unaspirated word (41.22 ms on average) The voice onset time of aspirated and unapirated words does not overlap. Besides, there is a statistically significant difference of .001 between the two, which can be used as a standard in distinguishing aspirated and unaspirated words. Moreover, the voice onset time suggests the difference between stops and affricates as well as the different sound-producing parts.4. Comparing the difference of voice onset time of aspirated and unaspirated words between hearing-impaired students and normal students. The voice onset time of aspirated and unaspirated words by hearing-impaired students is shorter than that by normal students, and there is a great dispersion. It is impossible to effectively distinguish aspirated and unaspirated words, difference of stops and affricates at different speech sections, the characteristic that the voice onset time of affricates is longer than that of stops, and words at different sound-producing parts.5. Types of sound-producing mistakes by hearing-impaired students The sound-producing mistakes by hearing-impaired students can be divided into the following five types: (1) vowelizing all words; (2) nasalizing all words; (3) aspirating all words; (4) slurring words; (5) insufficient aspirating time.