Because they have had some practice in hearing before birth, it is not surprising that infants have reasonably goodauditoryperceptionafter they are born. In fact, for certain very high and very low frequencies, infants actually are moresensitivetosoundthan adults—a sensitivity that seems to increase during the first two years of life. On the other hand, infants areinitiallylesssensitivethan adults to middle-range frequencies. Eventually, however, their capabilitieswithinthe middle rangeimprove.

It is not fullyclearwhat leads to the improvement duringinfancyin sensitivity to sounds, although it may be related to the maturation of the nervous system. More puzzling is why, afterinfancy, children’sabilityto hear very high and low frequenciesgraduallydeclines. One explanation may be thatexposureto high levels of noise maydiminishcapacities at theextremeranges.

Inadditionto theabilitytodetectsound, infants need several other abilities in order to hear effectively. Forinstance,soundlocalization permits infants topinpointthe direction from which asoundis emanating. Compared to adults, infants have aslighthandicap in this task, becauseeffectivesoundlocalization requires the use of theslightdifferencein the times at which asoundreaches our two ears. Because infants’ heads are smaller than those of adults, thedifferencein timing of the arrival ofsoundat the two ears is less than it is in adults. However, despite thepotentiallimitationbrought about by their smaller heads, infants’soundlocalization abilities are actuallyfairlygoodevenat birth, and theyreachadult levels of success by the age of one year. Interestingly, their improvement is not steady: although we don’t know why, theaccuracyofsoundlocalization actually declines between birth and two months of age, but then begins to increase.

Evenmore important to theirultimatesuccess in the world, young infants arecapableof making the fine discriminations that their future understanding of language willrequire. Forinstance, in oneclassicstudy, 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, theirinterestin thesoundmade themsuckvigorously. Soon, though, they became acclimated to thesoundand sucked with less energy. On the other hand, when the experimenters changed thesoundto “pa,” the infants immediately showed newinterestand sucked with greater vigor once again. Theclearconclusion: infants as young as one month old could make thedistinctionbetween the twosimilarsounds.

Evenmoreintriguingis the fact that young infants are able todiscriminatecertain characteristics thatdifferentiateone language from another. Someevidencesuggests thateventwo day olds show preferences for the language spoken by those around them over other languages. In the first few months, theabilitytodiscriminatebetween languages develops rapidly. By the age of five months, they candistinguishthedifferencebetween English and Spanish passages,evenwhen the two aresimilarin meter, number of syllables, and speed of recitation.

Giventheirabilitytodiscriminateadifferencein speech asslightas thedifferencebetween two consonants, it is not surprising that infants candistinguishdifferent people on the basis of voice. In fact, from an early age they showclearpreferences for some voices over others. Forinstance, in one experiment newborns were allowed tosucka nipple that turned on a recording of a human voice reading a story. The infants suckedsignificantlylonger when the voice was that of their mother than when the voice was that of a stranger.

How do such preferences arise? Onehypothesisis thatprenatalexposureto the mother’s voice is the key. As support for this conjecture, researchers point to the fact that newborns do not show apreferencefor their fathers’ voices over othermalevoices. Furthermore, newbornspreferlistening to melodies sung by their mothers before they were born to melodies that were not sung before birth. It seems, then, that theprenatalexposureto their mothers’ voices—although muffled by theliquidenvironment of thewomb—helpsshapeinfants’ listening preferences.

Questions:
question_stem: The word “initially”in the passage is closest in meaning to
choices: tag: A
text: usually

tag: B
text: at first

tag: C
text: to some extent

tag: D
text: basically
answer_key: B
explanation: initially adv.“最初，首先”，与 at first 同义。
故选 B。

question_stem: According to paragraph 1, which of the following statements does NOT accurately characterize auditory capability in infants?
choices: tag: A
text: Infants have good auditory capabilities in extreme frequencies rather than in middle frequencies.

tag: B
text: Infants have no experience with auditory stimuli before they are born.

tag: C
text: Infants are more capable of hearing high and low frequencies than adults are, and this capability increases during the first two years of life.

tag: D
text: An infant’s sensitivity to frequencies in the middle range improves as the infant grows older.
answer_key: B
explanation: 题干提问“以下哪个选项没有准确描述婴儿的听觉能力”，建议先看完四个选项，再逐一对应文本。
第1句 Because they have had some practice in hearing before birth，与选项 B 明显相反；
第2句 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 对应选项 C；
第3句 infants are initially less sensitive than adults to middle-range frequencies 对应选项 A；
第4句 their capabilities within the middle range improve 对应选项 D。
故选 B。

question_stem: Which of the following best describes the organization of paragraph 2?
choices: tag: A
text: A brief discussion of two changes in auditory perception together with possible explanations of them

tag: B
text: Two hypotheses about auditory perception, followed by summaries of experiments that have tested those hypotheses

tag: C
text: A brief history of studies of auditory perception, followed by a discussion of two recent studies

tag: D
text: A comparison of two different answers to an important question in the study of auditory perception
answer_key: A
explanation: 第1句 what leads to the improvement 提出问题，it may be related to 给出回答；第2句 why children’s ability to hear very high and low frequencies gradually declines 提出问题，第3句 One explanation may be 给出回答。
即 improvement、decline 为两种变化，分别给出相应解释，对应选项 A。
故选 A。

question_stem: According to paragraph 3, which of the following statements does NOT accurately characterize infants’sound-localization capabilities?
choices: tag: A
text: The sound-localization capabilities of infants do not improve steadily, but the reason for this is unknown.

tag: B
text: Infants’ ability to localize sound declines steadily after two months of age, but then increases after the age of one.

tag: C
text: The comparatively short distance between the ears of infants makes their sound localization potentially less exact than that of adults.

tag: D
text: By the age of one year, infants’ sound-localization capabilities are similar to those of adults.
answer_key: B
explanation: 题干提问“以下哪个选项没有准确描述婴儿声音定位能力”，建议先看完四个选项，再逐一对应文本。
第4句 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.对应选项 C；
第5句 they reach adult levels of success by the age of one year 对应选项 D；
第6句 their improvement is not steady: although we don’t know why 对应选项 A；
第6句 the accuracy of sound localization actually declines between birth and two months of age, but then begins to increase 对应选项 B，原文意为2个月后开始增加，选项意为1岁开始增加，表达不一致，错误。
故选 B。

question_stem: Which of the following statements describes a finding from the classic study on infants’auditory perception that is discussed in paragraph 4?
choices: tag: A
text: Infants are more interested in sounds of spoken language than they are in other kinds of sounds.

tag: B
text: Infants show more interest in some consonant sounds than others.

tag: C
text: When the sound infants are hearing is changed, the infants lose interest.

tag: D
text: Even very young infants are able to notice slight differences in sound.
answer_key: D
explanation: 题干提问“根据第4段讨论的婴儿听觉认知的经典研究，可得出以下哪个结果”。
由 classic study 定位第4段第2句，作为例子被提及，需找到例子的观点句后再解题，即第1句 young infants are capable of making the fine discriminations that their future understanding of language will require.
同时最后一句得出结论 The clear conclusion: infants as young as one month old could make the distinction between the two similar sounds.
首尾呼应，均讨论婴儿可以区分声音的细微差别，对应选项 D。
故选 D。

question_stem: The classic study discussed in paragraph 4 supports which of the following claims?
choices: tag: A
text: The infants’ sucking responses would have been different if a different pair of consonants had been used.

tag: B
text: The infants in the study had previous exposure to a language in which the difference between “ba” and “pa” is important.

tag: C
text: Infants are more interested in what is new or unexpected than they are in any particular consonant sound.

tag: D
text: Infants are able to produce the distinct consonant sounds that they hear as distinct.
answer_key: C
explanation: 题干提问“第4段讨论的婴儿听觉认知的经典研究可以支持以下哪个陈述”。
结合第5题已完成全段信息阅览，由实验中：婴儿起初听到 ba 声音感兴趣，随之失去兴趣，当听到 pa 的新声音后再次引起兴趣，可对应选项 C。
原文强调新声音带来的新兴趣，选项 A 的 sucking responses would have been different 未提及，选项 B 的 had previous exposure to a language 未提及，选项 D 的 able to produce the distinct consonant sounds 未提及。
故选 C。

question_stem: What is the main point of paragraph 5?
choices: tag: A
text: Very young children can distinguish between the sounds of different languages even though they cannot speak.

tag: B
text: Many children are exposed at an early age to both English and Spanish.

tag: C
text: Meter and speed of recitation are two characteristics children use to distinguish one language from another.

tag: D
text: Children recognize similar sounding words in different languages.
answer_key: A
explanation: 题干提问“第5段主旨”，段落主旨题一般会对应第1句的 topic sentence 即可。
第1句婴儿可以区分不同的语言，再结合下文的 two day olds，first few months，five months 体现出针对人群是 very young child。
故选 A。

question_stem: Why does the author discuss the voices of fathers and other males in paragraph 7?
choices: tag: A
text: To emphasize the difference between the auditory abilities before and after a child is born

tag: B
text: To provide evidence that infants' listening preferences are shaped by what they hear in the womb

tag: C
text: To argue that very young infants may have difficulty distinguishing between two similar-sounding voices

tag: D
text: To argue that infants are less interested in male voices than female voices
answer_key: B
explanation: 题干提问“作者为什么讨论爸爸和其他男性的声音”。
定位第7段第3句 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. 
根据 as support for this conjecture 得知 their fathers’ voices over other male voices 是作为论据支持 this conjecture；this conjecture 指代前一句 prenatal exposure to the mother’s voice is the key. 
再结合段尾句 the prenatal exposure to their mothers’ voices—although muffled by the liquid environment of the womb—helps shape infants’ listening preferences.
综合以上内容，均可得出其论点为婴儿的听力偏好会在产前就会受到影响。
故选 B。

question_stem: Paragraph 6 answers which of the following questions about the auditory abilities of infants?
choices: tag: A
text: What quality of a voice allows an infant to distinguish between different voices?

tag: B
text: Can newborns distinguish between tapes of their mother reading different stories?

tag: C
text: Can newborns distinguish between tapes of different strangers reading the same story?

tag: D
text: Can infants notice when the reader of a recorded story is changed?
answer_key: D
explanation: 题干提问“以下关于婴儿听觉能力的问题，哪一个可以在第6段得到答案”，建议先看完四个选项，了解四个问题的具体内容，再逐一对应文本。
选项 D 的问题可对应第6段后两句得到答案 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 longer when the voice was that of their mother than when the voice was that of a stranger.
故选 D。