本篇文章共分 7 段，從嬰兒對於高低頻聲音的聽覺能力、發音的分辨、語言的分辨、到人聲的分辨與偏好進行有系統的整理，說明新生嬰兒所展現的驚人聽覺感知能力。

本篇考題英文原文與對應之中文翻譯整理如下。練習作答解題時若有對語意不清楚之處，請仔細查閱對照，以提升閱讀理解能力。

Auditory Perception in Infancy 嬰兒期的聽覺感知

1. 嬰兒的聽覺感知能力優秀

   Because they have had some practice in hearing before birth, it is not surprising that infants have reasonably good auditory perception after they are born. In fact, for certain very high and very low frequencies, infants actually are more sensitive to sound than adults—a sensitivity that seems to increase during the first two years of life. On the other hand, infants are initially less sensitive than adults to middle-range frequencies. Eventually, however, their capabilities within the middle range improve.

   由於嬰兒在出生前就有一定的聽覺練習，所以他們在出生後有相當好的聽覺感知能力也就不足為奇。事實上，對於某些非常高和非常低的頻率，嬰兒實際上比成人對聲音更敏感—這種敏感度在嬰兒出生後的頭兩年似乎會增加。另一方面，嬰兒最初對中頻的敏感度比成人低。然而，最終，他們在中頻範圍內的能力有所提高。

2. 高低頻的聽覺能力下降

   It is not fully clear what leads to the improvement during infancy in sensitivity to sounds, although it may be related to the maturation of the nervous system. More puzzling is why, after infancy, children's ability to hear very high and low frequencies gradually declines. One explanation may be that exposure to high levels of noise may diminish capacities at the extreme ranges.

   目前還不完全清楚是什麼導致了嬰兒期對聲音敏感性的提高，儘管這可能與神經系統的成熟有關。更令人費解的是，為什麼在嬰兒期之後，兒童聽到非常高和低的頻率的能力逐漸下降。一種解釋可能是，暴露在高程度的噪音中可能會降低極端範圍的能力。

3. 嬰兒的聽覺定位能力

   In addition to the ability to detect sound, infants need several other abilities in order to hear effectively. For instance, sound localization permits infants to pin point the direction from which a sound is emanating. Compared to adults, infants have a slight handicap in this task, because effective sound localization requires the use of the slight difference in the times at which a sound reaches our two ears. Because infants' heads are smaller than those of adults; the difference in timing of the arrival of sound at the two ears is less than it is in adults. However, despite the potential limitation brought about by their smaller heads, infants' sound localization abilities are actually fairly good even at birth, and they reach adult levels of success by the age of one year. Interestingly, their improvement is not steady: although we don't know why, the accuracy of sound localization actually declines between birth and two months of age, but then begins to increase.

   除了檢測聲音的能力外，嬰兒還需要其他一些能力來發揮有效的聽覺。例如，聲音的定位使嬰兒能夠準確地指出聲音發出的方向。與成人相比，嬰兒在這項任務上有一點障礙，因為有效的聲音定位需要利用聲音到達我們兩隻耳朵的時間上的微小差異。因為嬰兒的頭比成人的小；聲音到達兩隻耳朵的時間差異比成人的要小。然而，儘管他們較小的頭部帶來了潛在的限制，嬰兒的聲音定位能力實際上甚至在出生時就相當好，他們在一歲時就能達到成人的水準。有趣的是，他們的進步並不穩定：雖然我們不知道為什麼：聲音定位的準確性在出生後到兩個月大時實際上是下降的，但隨後開始上升。

4. 嬰兒的近似音分辨能力

   Even more important to their ultimate success in the world, young infants are capable of making the fine discriminations that their future understanding of language will require. For instance, in one classic study, a group of one to four-month-old infants sucked on nipples that activated a recording of a person saying “ba” every time they sucked. At first, their interest in the sound made them suck vigorously. Soon, though, they became acclimated to the sound and sucked with less energy. On the other hand, when the experimenters changed the sound to “pa”, the infants immediately showed new interest and sucked with greater vigor once again. The clear conclusion: infants as young as one month old could make the distinction between the two similar sounds.

   對於他們在這個世界上的最終成功來說，更重要的是，年輕的嬰兒有能力進行精細的辨別，這是他們未來對語言的理解所需要的。例如，在一項經典的研究中，一組一至四個月大的嬰兒吸吮乳頭，每次吸吮都會激發一個人說 “ba” 的錄音。起初，他們對這個聲音的興趣使他們大力吸吮。但很快，他們就適應了這種聲音，吸吮的力度也變小了。另一方面，當實驗者將聲音改為 “pa” 時，嬰兒立即表現出新的興趣，並再次以更大的力氣吸吮。明確的結論是：一個月大的嬰兒就能區分這兩種類似的聲音了。

5. 嬰兒的語言分辨能力

   Even more intriguing is the fact that young infants are able to discriminate certain characteristics that differentiate one language from another. Some evidence suggests that even two-day-olds show preferences for the language spoken by those around them over other languages. In the first few months, the ability to discriminate between languages develops rapidly. By the age of five months, they can distinguish the difference between English and Spanish passages, even when the two are similar in meter, number of syllables, and speed of recitation.

   更耐人尋味的是，年幼的嬰兒能夠分辨出區分一種語言和另一種語言的某些特徵。一些證據顯示，即使是兩天大的孩子也會表現出對周圍人所說的語言比上其他語言的偏好。在最初的幾個月裡，辨別語言的能力發展迅速。到 5 個月大時，他們可以區分英語和西班牙語的文章，即使這兩種語言在節拍、音節數和朗誦速度上相似。

6. 嬰兒的人聲分辨能力

   Given their ability to discriminate a difference in speech as slight as the difference between two consonants, it is not surprising that infants can distinguish different people on the basis of voice. In fact, from an early age they show clear preferences for some voices over others. For instance, in one experiment newborns were allowed to suck a nipple that turned on a recording of a human voice reading a story. The infants sucked significantly Ionger when the voice was that of their mother than when the voice was that of a stranger.

   鑒於他們有能力辨別像兩個子音之間的差異這樣微小的語音差異，嬰兒能夠根據聲音區分不同的人就不足為奇了。事實上，從很小的時候起，他們就表現出對某些聲音的明顯偏好。例如，在一個實驗中，新生兒被允許吸吮一個乳頭，這個乳頭打開了一個人聲讀故事的錄音。當聲音是他們母親的時候，嬰兒的吸吮時間明顯比陌生人的聲音要長。

7. 人聲偏好產生的原因

   How do such preferences arise? One hypothesis is that prenatal exposure to the mother's voice is the key. As support for this conjecture, researchers point to the fact that newborns do not show a preference for their fathers' voices over other male voices. Furthermore, newborns prefer listening to melodies sung by their mothers before they were born to melodies that were not sung before birth. It seems, then, that the prenatal exposure to their mothers' voices—although muffled by the liquid environment of the womb—helps shape infants' listening preferences.

   這種偏好是如何產生的？一種假設是，產前接觸到母親的聲音是關鍵所在。作為對這一猜想的支持，研究人員指出，新生兒並沒有表現出對父親的聲音比其他男性的聲音更偏愛的事實。此外，新生兒更喜歡聽他們出生前母親唱的旋律，而不是出生前沒有唱過的旋律。那麼，似乎產前接觸母親的聲音—儘管被子宮的液體環境所掩蓋—有助於塑造嬰兒的聆聽偏好。