Rebecca E. Eilers

The Role of Audition in Infant Babbling.

The traditional belief that audition plays only a minor role in infant vocal development depends upon evidence that deaf infants produce the same kinds of babbling sounds as hearing infants. Evidence in support of this position has been very limited. A more extensive comparison of vocal development in deaf and hearing infants indicates that the traditional belief is in error. Well-formed syllable production is established in the first 10 months of life by hearing infants but not by deaf infants, indicating that audition plays an important role in vocal development. The difference between babbling in the deaf and hearing is apparent if infant vocal sounds are observed from a metaphonological perspective, a view that takes account of the articulatory/acoustic patterns of speech sounds in all mature spoken languages.

Language and literacy in bilingual children

Section A: Background 1. Assessing the Effects of Bilingualism - D. K. Oller and B.Z. Pearson 2. An Integrated Approach to Evaluating Effects of Bilingualism in Miami School Children - D. K. Oller and R. E. Eilers. Section B: Overall Results on Language use and Standardized Test Performance 3. Bilingualism and Cultural Assimilation in Miami Hispanic Children -R. E. Eilers, D. K. Oller and A. B. Cobo-Lewis 4. Effects of Bilingualism and Bilingual Education on Oral and Written English Skills -A. B. Cobo-Lewis, B. Z. Pearson, R. E. Eilers, and V. C. Umbel 5. Effects of Bilingualism and Bilingual Education on Oral and Written Spanish Skills - A. B. Cobo-Lewis, B. Z. Pearson, R. E. Eilers, and V. C. Umbel 6. Interdependence of Spanish and English Knowledge in Language and Literacy among Bilingual Children - A. B. Cobo-Lewis and R. E. Eilers. Section C: Probe Studies on Complex Language Capabilities 7. Narrative Competence among Monolingual and Bilingual School Children in Miami -B. Z. Pearson 8. Command of the Mass/count Distinction in Bilingual and Monolingual Children -V. C. Mueller Gathercole 9. Grammatical Gender in Bilingual and Monolingual Children - V. C. Mueller Gathercole 10. Monolingual and Bilingual Acquisition -V. C. Mueller Gathercole 11. The Ability of Bilingual and Monolingual Children to Perform Phonological Translation - D. K. Oller and A. B. Cobo-Lewis. Section D: A Retrospective View of the Research 12. Balancing Interpretations Regarding Effects of Bilingualism - D. K. Oller and R. E. Eilers

Innateness, Experience, and Music Perception

Musical acculturation from infancy to adulthood was studied by testing the abilities of Western 6-month-olds and adults to notice mistunings in melodies based on native Western major, native Western minor, and non-native Javanese pelog scales. Results indicated that infants were similarly able to perceive native and non-native scales. Adults, however, were generally better perceivers of native than non-native scales. These findings suggest that infants are born with an equipotentiality for the perception of scales from a variety of cultures and that subsequent culturally specific experience substantially influences music perception.

Similarity of Babbling in Spanish- and English-Learning Babies.

Infants from a variety of linguistic backgrounds have been reported to babble similarly. The present study considers this possibility in detail, offering a concrete characterization of how babbling of Spanish- and English-learning babies is similar. Babbling of a group of Spanish- and another of English-learning infants (12 months of age) was recorded and transcribed by two experimenters, one a primarily Spanish speaker and one a primarily English speaker. Results show that in spite of gross phonetic differences between the adult phonologies of Spanish and English, babies from both groups produce predominantly CV syllables with voiceless, unaspirated plosive consonants. Vowel production is also perceived as notably alike. In the light of such similarities, possible differences in babbling of the two groups may be hard for even sophisticated listeners to notice.

Development of precursors to speech in infants exposed to two languages

The study of bilingualism has often focused on two contradictory possibilities: that the learning of two languages may produce deficits of performance in each language by comparison with performance of monolingual individuals, or on the contrary, that the learning of two languages may produce linguistic or cognitive advantages with regard to the monolingual learning experience. The work reported here addressed the possibility that the very early bilingual experience of infancy may affect the unfolding of vocal precursors to speech. The results of longitudinal research with 73 infants aged 0;4 to 1;6 in monolingual and bilingual environments provided no support for either a bilingual deficit hypothesis nor for its opposite, a bilingual advantage hypothesis. Infants reared in bilingual and monolingual environments manifested similar ages of onset for canonical babbling (production of well-formed syllables), an event known to be fundamentally related to speech development. Further, quantitative measures of vocal performance (proportion of usage of well-formed syllables and vowel-like sounds) showed additional similarities between monolingual and bilingual infants. The similarities applied to infants of middle and low socio-economic status and to infants that were born at term or prematurely. The results suggest that vocal development in the first year of life is robust with respect to conditions of rearing. The biological foundations of speech appear to be such as to resist modifications in the natural schedule of vocal development.

The role of prematurity and socioeconomic status in the onset of canonical babbling in infants

The onset of canonical babbling (implying production of well-formed syllables) is a landmark event in the development of the capacity for speech, capping a series of vocal stages of the infants first year of life. Infants who are handicapped with regard to linguistic development are, in some cases, delayed in the onset of speech-like sounds such as canonical syllables. The age of onset of canonical babbling in infants born at risk, either due to prematurity or due to low socioeconomic status (SES) has not been extensively studied. This research, based on a longitudinal investigation of babbling and other motor milestones in term and preterm infants of middle and low SES, indicates that the onset of canonical babbling is robust with regard to such risk factors. Neither preterm infants whose ages were corrected for gestational age, nor infants of low SES were delayed in the onset of canonical babbling. In fact, at corrected ages, the preterm infants appeared to begin canonical babbling earlier than their full-term counterparts. It is suggested that the greater auditory experience of the preterms in this study may account for the early appearance of canonical babbling and hand banging, both of which can be viewed as rhythmic stereotypies that may require auditory feedback for normal development. Other motor milestones studied showed neither delay nor acceleration of onset in the same infants.

Speech-like vocalizations in infancy: an evaluation of potential risk factors [*]

This work reports longitudinal evaluation of the speech-like vocal development of infants born at risk due to prematurity or low socio-economic status (SES) and infants not subject to such risk. Twenty infants were preterm (10 of low SES) and 33 were full term (16 of low SES), and all were studied from 0;4 through 1;6. The study provides the indication that at-risk infants are not generally delayed in the ability to produce well-formed speech-like sounds as indicated in tape-recorded vocal samples. At the same time, premature infants show a tendency to produce well-formed syllables less consistently than full terms after the point at which parents and laboratory personnel note the onset of the canonical babbling stage (the point after which well-formed syllables are well established in the infant vocal repertoires). Further, even though low SES infants produce well-formed speech-like structures on schedule, they show a reliably lower tendency to vocalize in general, as reflected by fewer utterances per minute in recorded samples.

Late Onset Canonical Babbling: A Possible Early Marker of Abnormal Development.

By their 10th month of life, typically developing infants produce canonical babbling, which includes the well-formed syllables required for meaningful speech. Research suggests that emerging speech or language-related disorders might be associated with late onset of canonical babbling. Onset of canonical babbling was investigated for 1,536 high-risk infants, at about 10-months corrected age. Parental report by open-ended questionnaire was found to be an efficient method for ascertaining babbling status. Although delays were infrequent, they were often associated with genetic, neurological, anatomical, and/or physiological abnormalities. Over half the cases of late canonical babbling were not, at the time they were discovered associated with prior significant medical diagnoses. Late canonical-babbling onset may be a predictor of later developmental disabilities, including problems in speech, language, and reading.

A study of perceptual development for musical tuning

Musical tuning perception in infancy and adulthood was explored in three experiments. In Experiment 1, Western adults were tested in detection of randomly located mistunings in a melody based on musical interval patterns from native and nonnative musical scales. Subjects performed better in a Western major scale context than in either a Western augmented or--a Javanese pelog scale context. Because the major scale is used frequently in Western music and, therefore, is more perceptually familiar than either the augmented scale or the pelog scale are, the adults’ pattern of performance is suggestive of musical acculturation. Experiments 2 and3 were designed to explore the onset of culturally specific perceptual reorganization for music in the age period that has been found to be important in linguistically specific perceptual reorganization for speech. In Experiment 2, 1-year-olds had a pattern of performance similar to that of the adults, but 6-month-olds could not detect mistunings reliably better than chance. In Experiment 3, another group of 6-month-olds was tested, and a larger degree of mistuning was used so that floor effects might be avoided. These 6-month-olds performed better in the major and augmented scale contexts than in the pelog context, without a reliable performance difference between the major and augmented contexts. Comparison of the results obtained with 6-month-olds and 1-year-olds suggests that culturally specific perceptual reorganization for musical tuning begins to affect perception between these ages, but the 6-month-olds’ pattern of results considered alone is not as clear. The 6-month-olds’ better performance on the major and augmented interval patterns than on the pelog interval pattern is potentially attributable to either the 6-month.olds’ lesser perceptual acculturation than that of the 1-year-olds or perhaps to an innate predisposition for processing of music based on a single fundamental interval, in this case the semitone.

The Role of Speech Discrimination in Developmental Sound Substitutions.

Fourteen two-year-olds (M=2; o) were presented with minimal word pairs in a new and highly efficient experimental perception paradigm. The data provide a preliminary view of the relative difficulty of various minimal phonological contrasts for children. The study specifically focuses on perception of some phonological contrasts which usually are actualized and some which usually are not actualized in two-year-old child productions. The data suggest that perceptual difficulties probably play a substantial role in some childhood speech errors, but little, if any, role in others.