The Un-trained Ear

Language acquisition was the theme of our lecture this week, and the unbounded linguistic potential of infants was an important topic.  Examining broad theories of language acquisition, we first discussed Chomsky's ideas of the "Language Acquisition Device."  What he believed to be human's innate, biologically based mental structure for the acquisition of language.  This was contrasted with Bruner's theory of the Language Acquisition Support System (LASS); the idea that language develops only in a social context, guided and supported by parents and other caregivers.

One important example introduced within this theoretical clash was Janet Werker's study of phonological perception in infants (Developmental Aspects of Cross-Language Speech Perception

Janet F. Werker, John H. V. Gilbert, Keith Humphrey and Richard C. Tees, Child Development Vol. 52, No. 1 (Mar., 1981), pp. 349-355 ).  

Werker studied infants from non-Hindi speaking families and measured their abilities to discriminate a phoneme present in Hindi but not present in English.  You can listen to the difference between these phonemes in this online Hindi lesson.  A Phoneme is the smallest unit of sound within a language that can convey meaning.  Although there are hundreds of phonemes possible, each language uses its own select and limited sample to construct its phonology.  

In both longitudinal and cross-sectional studies, Werker found that infants at ages 6-8 months were able to recognize the difference between the two sounds, but that by 8-10 months, infants from non-Hindi speaking families had lost the ability to discern the Hindi phonemes.

Theoretically, this seems to support Chomsky's ideas, as we see that infants have an innate and almost unlimited ability to listen and discern differences in phonetic sounds.  As for Bruner's Social-cultural theory, in the limited case phonological discrimination, it seems that the Language Acquisition Support System is more destructive than constructive.  The child's social surroundings reinforce only the phonological productions of their native language, and the child's broad ability to discern the entire breath of human phonology withers away.

I had more than a merely academic interest in this topic, especially since Werker's study focused on Hindi.  As I have mentioned in a previous post, my wife is from India.  Although she is most comfortable speaking English, she is fluent in Hindi as well.  I know only a few words of Hindi.  As we raise our two children here in the US, we are always mindful of how to keep them in touch with their Indian heritage.  Language, of course is integral to this process.  

Our oldest child is 5, and has already passed the "sensitive period" where he could have learned to discriminate all of the sounds of Hindi.  I'm doubtful that he heard the language regularly and often enough to learn them.  He has also just begun kindergarten, and his wholehearted commitment to English phonology in concert with his efforts to learn to read make him resistant to other sounds.  Our daughter, on the other hand, is just turning 6 months old.  She is right in the middle of the sensitive period that Werker describes, where all phonological sounds are still distinct in her un-trained ear.  Unfortunately, all the pressure is on my wife to impart this ability to her.  As I never learned Hindi in my youth, I can't discriminate the sounds, nor can I re-create them accurately.