撰文：香港言語及吞嚥治療中心 言語治療師 李詠茵
筆者曾在工作上遇到一位 5 歲的小朋友。他跟其他同齡的孩子一樣，外表乖巧，而且十分有禮貌。但他有著與其他同齡孩子不同的特徵－ 他的左耳配上了一個助聽器。他，也是一個患有聽力障礙的孩子。
顧名思義，聽力障礙的定義為「因聽力受損而成的障礙，包括弱聽至完全失聰」。那聽力障礙是否只影響孩子的聽覺呢？
理解四周聲音 建立概念
試想想，幼兒在學會說出有意思的字詞前，會先有甚麼能力呢？那是說「BB話」吧。那麼幼兒在學會說「BB話」前，其中重要的一步又是甚麼呢？是學會理解四周環境的聲音，以及透過與聲音（包括父母有意思的說話、兒歌等）的互動而建立概念，明白不同語音代表著不同的人、事和物，從而逐步理解字詞，建立語言。因此，由於有聽力障礙的幼兒在「聽」方面接受的感官刺激比正常聽力的幼兒較少和弱，因此也有機會導致語言發展遲緩。
減少聆聽經驗 難以跟從指令
聽力障礙的兒童未能從「聽」的感官方面完全接收外界訊息，減少了聆聽經驗和語言接觸的機會，因而往往出現不專心的情況，難以跟從指令，以及在理解較複雜的句式時會出現困難，影響學習。由於語言學習的發生是透過留意和接收外界的輸入，再經過重覆接收類同的訊息與特定概念的連繫、模仿和運用。因此，不少聽力障礙的孩子長大後，在語法運用、句式表達和詞語認識會比其他孩子較弱，更有研究指出兩者在詞語認識上的差距，會隨著年紀而愈來愈大。
Written by: Lee Wing Yan, Speech Therapist at the Hong Kong Speech and Swallowing Therapy Centre
In my work, I once encountered a 5-year-old child. Like other children of his age, he appeared well-behaved and polite. However, he had a distinctive feature that set him apart from his peers – he had a hearing aid in his left ear. He was a child with a hearing impairment.
As the name suggests, hearing impairment is defined as a “disability caused by impaired hearing, ranging from mild to complete deafness.” Does hearing impairment only affect a child’s auditory perception?
Understanding Surrounding Sounds to Build Concepts
Consider this: before toddlers learn to articulate meaningful words, what ability do they possess? They engage in what we commonly refer to as “baby talk.” Now, what crucial step do toddlers take before mastering “baby talk”? It’s the ability to understand the sounds in their environment and establish concepts through interaction with sounds, including meaningful conversations with parents, nursery rhymes, etc. They learn to comprehend that different sounds represent different people, things, and objects, gradually understanding words and building language. Therefore, due to reduced and weaker sensory stimulation in the aspect of “hearing,” children with hearing impairment may experience delayed language development.
Reduced Listening Experience and Difficulty Following Instructions
Children with hearing impairment cannot fully receive external information through the sensory aspect of “hearing,” reducing opportunities for listening experiences and language exposure. As a result, they often exhibit inattentiveness, difficulty following instructions, and challenges in understanding more complex sentence structures, affecting their learning. Language learning occurs through paying attention and receiving external input, followed by repeated exposure to similar information, connecting specific concepts, imitation, and application. Consequently, many children with hearing impairment may exhibit weaknesses in grammar usage, sentence expression, and vocabulary recognition compared to other children. Research even suggests that the gap in vocabulary recognition between the two groups tends to widen with age.
影響語音發展 難察覺聲調間的分別
而聽力障礙對幼童語言發展的另一更明顯的影響，則是其語音發展。一般聽力障礙的兒童往往對於較高頻率（frequency）和低強度（intensity）語音的敏感度低，因此未會留意到這些語音，就如粵語包含 /f/、/s/、/ts/、/tsh/ 音的字（例如：「飛」、「三」、「吱」、「車」），並以其他語音代替，如將「飛」讀成「悲」、「三」讀成「擔」、「吱」讀成「啲」、「車」讀成「爹」等。由於此類的錯音源自孩子的聽力障礙，而因此對某些字音的敏感度低，所以孩子未必能自行察覺到自己發音上的錯誤，或自己的發音與他人的分別。
Impact on Speech Development: Difficulty Perceiving Differences in Tone
Another more noticeable effect of hearing impairment on the language development of young children is its impact on speech development. Children with hearing impairment often have lower sensitivity to higher-frequency and lower-intensity speech sounds. Consequently, they may not pay attention to these sounds, such as the Cantonese sounds /f/, /s/, /ts/, and /tsh/ found in words like “fei”（飛）, “saam”（三）, “zi”（吱）, and “che”（車）. Instead, they may substitute other sounds, such as pronouncing “fei” as “bei,” “saam” as “daam,” “zi” as “di,” and “che” as “dei.” Since these pronunciation errors stem from the child’s hearing impairment and their lower sensitivity to certain phonemes, the child may not necessarily be aware of the pronunciation mistakes they make or the differences between their pronunciation and that of others.
另一方面，粵語是一種「聲調語言」(tonal language)，一般來說有九個聲調。聲調之間的差異很細微，因此正如咬字發音一樣，聽力障礙的孩子也可能因為對各聲調的敏感度較低，而未有察覺它們之間的分別，旁人聽起來，可能會覺得孩子的說話如外國人說話或唱歌一般。
及早介入 接受治療
當然，並不是每一個有聽力障礙的孩子也會面對語言發展遲緩或咬字發音的問題，筆者也曾經接觸不少語言能力十分優秀的聽障小朋友和成年人。正如其他健康問題一樣，「及早介入」才是處理問題的關鍵。因此，假若懷疑孩子有任何聽力問題，便應盡早接受耳鼻喉科醫生和聽力學家的評估，以決定是否需要配置助聽器或接受其他治療。假若孩子真的患有聽力問題，單靠配戴助聽器也未必可以完全解決或避免與聽力障礙有關的語言發展問題。因此，也應盡早接受適合的言語治療，使孩子的語言發展能及早趕上同齡孩子。
On the other hand, Cantonese is a “tonal language” with generally nine tones. The differences between tones are subtle, similar to nuances in pronunciation. Children with hearing impairment may also fail to perceive the distinctions between tones due to their lower sensitivity, much like in articulating individual sounds. To others, the child’s speech might sound akin to a foreigner speaking or singing.
Early Intervention and Therapy
Of course, not every child with hearing impairment will experience delays in language development or pronunciation issues. I have encountered many hearing-impaired children and adults with excellent language abilities. Like any health issue, “early intervention” is the key to addressing problems. Therefore, if there is suspicion of any hearing issues in a child, an early assessment by an otolaryngologist and audiologist is crucial to determine whether hearing aids or other treatments are needed. If a child indeed has hearing problems, relying solely on hearing aids may not completely resolve or prevent language development issues associated with hearing impairment. Therefore, early and appropriate speech therapy should also be sought to ensure the child’s language development catches up with their peers as soon as possible.
