Directed speech from the mother to the child adapts and the child’s language matures as motherese is well tuned to the child’s language level (Owens, 1986). The rate of change in language level is initially slow however it speeds up with age. The complexity and the length of the mother’s utterances most primarily change between twenty and twenty-seven months alongside the period of rapid language change for the child. However, at any given time the syntax is mostly consistent (Wells et. al., 1983).
Infant-directed speech also is altered at the phonetic level and these alterations are argued to help infants learn. In a recent study, women were recorded while speaking to their two-month-old infants and to another adult in the United States, Russia, and Sweden (Kuhl, 1997). Mothers used the vowels /i/, /a/, and /u/, in both settings, and their speech was analysed. The results demonstrated that the phonetic units of infant-directed speech are acoustically exaggerated. The results show a stretching of the acoustic space encompassing speech. Exaggerating speech not only makes it more distinguishable for infants, it highlights critical parameters used in the native language. This may aid the childs discovery of the dimensions of sound used in their native language. Mothers addressing infants also increase the variety of exemplars they use, behaving in a way that makes them resemble many different talkers is a feature shown to assist category learning in second-language learners (Lively, 1993). In recent studies, language-delayed children show substantial improvements in measures of speech and language after listening to speech altered by computer to exaggerate phonetic differences (Merzenich, 1996)
Mothers addressing infants make other adjustments that appear to aid learning. When introducing new words, parents repeat the word often in stereotyped frames (“Where's the __ ,” “See the __ ,” “That's a __ ” (Peters, 1983), which highlights the items in sentence-final position. They also present new words in a great variety of contexts, which would highlight the transitional probabilities of the new words against a variety of contexts (Goodsitt, 1993). This data suggests that the modifications made by adults unconsciously when they speak to infants plays a role in helping infants map native-language input.
Motherese involves many re-casts by the adult. Re-casts occur when an adult repeats a child's speech, while adding complexity and expanding vocabulary. Re-casts expose the child to new forms and structures, while providing more fuel for language acquisition than would immediate imitation (Goodluck, 1986). An example of a re-cast is a child saying “up” whilst the mother follows with “yes, mummy will pick you up”. In these re-casts there is also a tendency to avoid using personal pronouns such as "I" and "you" since both can be very confusing to the child. It is difficult for the child to recognise that "you" can be applied to more than one person hence, the parent most often than not refers to both herself and the child using the respective nouns "mummy" and "child" for example.
In both English and French the amount of parental labeling or naming varies with the age and development of the child but a relationship still exists between the amount of adult labeling and the child’s consequent growth in vocabulary (Graham & Sippola, 1995). Choi & Gopnik (1995) produced evidence to suggest that initial parental emphasis on nouns from Mandarin, Korean, Italian, and English is not universal although gesturing and use of noun labels in English decrease with development regardless. Nouns become replaced with verbs to describe actions being performed by objects (Schmidt, 1996).
The steady rhythmic flow of the dialog depends on the structural resemblance of the mother and child utterances as well as on the association of the mother’s speech relative to the environment. Through the use of turn-passing strategies the mother encourages and allows the child to participate however refrains from using turn-grabbing or turn-keeping behaviours. Consequently, the child is not a solo linguist with the endeavor to learn the language code; the large majority of the analysis, synthesis and abstraction is performed by the mother (Moerk, 1985).
Undeniably, the language input and motherese to which is child is subject to is influenced by the child’s characteristics (Yoder & Kaiser, 1989). The types of toys children chose to play with or are presented with, can manipulate the amount and types of language produced by the mother (O’Brien & Nagle, 1987), dolls for example promote role play and hence promote larger amounts and variety of language from parents. Furthermore, simplifications to language by adults logically must reflect cues from the child, although parents aren’t aware of their alterations as they are not consciously trying to teach a language. Not only is much of the speech addressed to the child adapted for the child’s linguistic level according to the amount of child feedback and participation but speech not adapted is simply not processed by the child (Snow, 1986). In effect, children play an active and important role in choosing the utterances to which they will respond. Lack of response from the child informs the parent that communication has broken down, which may instigate the linguistic changes in the parent to take place. It is logical to conclude the key to adult linguistic changes is the child (Furrow & Nelson, 1984).
The pragmatic aspects to the mother’s speech are likely to be related to either the referential or the expressive style of the child as referential children tend to name frequently whereas expressive children participate in more conversation. Mother’s to referential children use more descriptive words with fewer directives, additionally, these mother’s make more utterances in a given situation then mother’s with expressive speech (Benedict & Klein, 1983).
Furthermore, Ochs & Schieffelin (1994) report children do not require a syntactically and phonologically simplified input in order to acquire language, as the use of motherese is not universal across all cultures, however it is still very widespread regardless. There also seems to exist a great variation in the styles of social interaction and the form of motherese across different cultures (Lieven, 1994). However, it is possible that these other cultures compensate for their lack of motherese through simplifying language development in other ways, such as via emphasizing everyday communal life (Snow, 1995).
The rate of a child’s linguistic development is only not correlated with the complexity of the child’s input. The most important factor to motherese isn’t the form of what it directly said to the child but the content, in particular, children who learn the fastest are those who receive most encouragement and acknowledgment for their utterances (Ellis & Wells, 1980). Gross (1978) demonstrated the value of extended replied by adults that in result amplify the comments of the children. This conclusion was drawn because, children who showed the most rapid linguistic development were those whose mother’s asked their children more questions and gave more extensive replies to their children’s questions (Howe, 1980).
In conclusion, much remains to be learned about language acquisition however it can be deduced that motherese is beneficial to a child's acquisition of language regardless of whether it is completely necessary for language development or not. The aim of motherese may not be to teach language however it facilitates development through providing an opportunity for children to practice, improve, and enhance their language abilities. The caregiver’s efforts combined with the child’s own influences produce a suitable relationship for the input, feedback, acquisition and practice of language. Motherese may also serve to aid a child in the acquisition and comprehension of language particular rules which are otherwise largely unpredictable principles of universal grammar. However, factors such as socio-economic background, where toys promoting language utilasation cannot be bought will hinder the effects of motherese regardless of whether motherese is in effect or not; birth order, position in the family, and siblings also have an effect on early language development, this is because single children have a greater opportunity to communicate effectively with adults as compared to children with many siblings as may therefore develop language at a faster pace. Ethnicity, parents’ mother tongue and parents’ work hours are more examples of factors that directly affect the success motherese can have on children’s language development. Consequently, for a child to fully benefit from the effects of motherese he/she must boast optimal conditions, if this is not possible, as is the case with many individuals, motherese may not act as beneficially as possible, however it will still serve to assist in language acquisition.
References
Bernstein Ratner, N., & Pye, C. (1984). Higher Pitch in BT is not universal: Acoustic evidence from Quiche Mayan. Journal of Child Language, 11, 515-522.
Bruner (1978). Learning how to do things with words. In J. Bruner & A. Gurton (Eds.), Wolfson Collge Lectures 1976: Human Growth and Development. Oxford: Oxford University Press
Choi, S., & Gopnik, A. (1995). Early acquisition of verbs in Korean: A cross linguistic study. Journal og Child Language, 22, 297-529.
Ellis, R., & Wells, G.(1980). Enabling factors in adult-child discourse. First Language, 1, 46-62.
Ferguson, C. A. (1964). Am. Anthropol. 66, 103114.
Fernald, A. (1985). Four-month old infants prefer to listen to motherese. Infany Behavior and Development, 8, 181195.
Fernald, A., (1994). Human maternal vocalizations to infants as biologically relevant signals: An evolutionary perspective. In P. Bloom (Ed.), Language acquisition: Core readings. Cambridge, MA: MIT Press.
Fernals, A., & Kuhl, P. (1987). Fundamental frequency as an acoustic determinant of infant preference for motherese. Paper presented at a meeting for Research into Child Development.
Furrow, D., & Nelson, K.(1984). Environmental correlates of individual differences in language acquisition. Journal of Child Language, 11, 523-534.
Goodluck, H. (1986). Language acquisition and linguistic theory. In P. Fletcher & M. Garman (Eds.), Language acquisition (2nd ed.). New York: Cambridge University Press.
Goodsitt, J. V., Morgan, J. L., & Kuhl, P. K. (1993). J. Child Lang. 20, 229252.
Harley, T. (2001). The Psychology of Language. U.S.A.: Psychology Press.
Howe, C. (1980). Language learning from mothers’ replies. First Language, 1, 83-97.
Kuhl, P. K., Andruski, J. E., Chistovich, I. A., Chistovich, L. A., Kozhevnikova, E. V., Ryskina, V. L., Stolyarova, E. I., Sundberg, U., & Lacerda, F. (1997). Science 277, 684686.
Lieven, E.V.M. (1994). Crosslinguistic and crosscultural aspects of language addressed to children. In C. Gallaway & B.J. Richards (Eds.), Input and interaction in language acquisition (pp. 56-73). Cambridge: Cambridge University Press.
Lively, S. E., Logan, J. S., & Pisoni, D. B. (1993). J. Acoust. Soc. Am. 94, 12421255
Merzenich, M. M., Jenkins, W. M., Johnston, P., Schreiner, C., Miller, S. L., & Tallal, P. (1996). Science 271, 7781.
Moerk, E. (1985). Analytic, synthetic, abstracting and word-class-defining aspects of verbal mother-child interactions. Journal of Psycholinguistic Research, 14, 239-252.
Murray, A., Johnson, J., & Peters, J. (1990). Fine-tuning of utterance length to preverbal infants: Effects on later language development. Journal of Child Language, 17, 511-525.
Newport, E., Gleitman, A., & Gleitman, L. (1977). Mother I’d rather do it myself: Som effects and non-effects of maternal speech style. In C. Snow & C. Ferguson (Eds.), Talking to children: Language input and acquisition. New York: Cambridge University Press.
Ochs, E., & Schiefflin, B. (1984) Language acquisition and socialization: Three developmental stories and their implications. In R. Shweder & R. Levine (Eds.), Culture and its acquisition. New York: Cambridge University Press.
O’Brien, M., & Nagle, K. (1987). Parents’ speech to toddlers: The effect of play context. Journal of Child Language, 14, 269-279.
Owens, R. (1986). Communication, language and speech. In G. Shames & E. Wiig (Eds.), Human communication disorders. Columbus, OH: Merrill.
Owens, R. (1996). Language and Development: An Introduciton. U.S.A.: Allyn and Bacon.
Peters, A. M. (1983) in The Units of Language Acquisition (Cambridge Univ. Press, Cambridge).
Rondal, J., & Cession, A. (1990). Input evidence regarding the semantic bootstrapping hypotheses. Journal of Child Language, 17, 711-717.
Sachs, J. (1985). Prelinguistic Development. In J. Berko Gleason (Ed.), The development of language. Columbus, OH: Merrill.
Schmidt, C. L. (1996. Scrutinizing reference: How gesture and speech are co-ordinated in mother-cchild interaction. Journal of Child Language, 4, 153-169.
Snow, C. (1986). Conversations with children. In P. Fletcher & M. Garman (Eds.), Language Acquisition (2nd ed.). New York: Cambridge University Press.
Snow, C.E. (1994). Beginning from baby talk: Twenty years of research on input and interaction. In C. Gallaway & B.J. Richards (Eds.), Input and interaction in language acquisition (pp. 3-12). Cambridge: Cambridge University Press.
Wells, G., Barnes, S., Gutfreund, M., & Satterly, D. (1983). Characteristics of adult speech which predict children’s language development. Journal of Child Language, 10, 65-84.
Yoder, P., & Kaiser, A. (1989). Alternative explanations for the relationship between maternal verbal interaction style and child language development. Journal of Child Language, 16, 141-160.