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Biomedical subjects

R E Eilers

Publications and source records attributed to R E Eilers.

52 records · Page 3Linked to original sources

The discrimination of vowel duration by infants.

Three groups of nine 5-11-month-old infants provided evidence of discrimination of speechlike stimuli differing only in vowel duration. Ease of discrimination was directly related to the magnitude of the ratio of the longer to shorter vowel. Group one infants discriminated three vowel duration contrasts (with ratios of 0.33, 0.67, and 1.0) embedded in a synthetic [mad] syllable; group two discriminated these same duration contrasts within the bisyllable [ samad ], and group three in the trisyllable [ masamad ]. In all cases, the contrasting durations were carried by the last vowel of the synthetic word. These same three infant groups failed to provide evidence of discrimination of a final position released stop consonant contrast ([mat] versus [mad]) cued by voice excitation during closure of the [d] and not the [t]. These results suggest that vowel duration may be a primary cue for infants' perception of the voicing of final position stop consonants.

Adult↗

Infants' discrimination of intensity variation in multisyllabic stimuli.

Two groups of 5- to 11-month-old infants were tested for their ability to discriminate within-utterance intensity variations similar to those associated with linguistic stress. A visually reinforced discrimination procedure was used to determine sensitivity to increments in peak intensity for a final position, synthetic CVC syllable within either a bisyllabic (CVCVC) or a trisyllablic (CVCVCVC) context. Discrimination performance was above chance for a 2-dB increment, and improved for 4- and 6-dB increments. In addition, infants were more sensitive to intensity increments in the bisyllablic as compared to the trisyllabic context. Infant sensitivity for within-utterance intensity variations is sufficient for the detection of some linguistic stress contrasts.

Cues↗

Speech identification in Spanish- and English-learning 2-year-olds.

English- and Spanish-learning 2-year-olds were tested for speech skills in a real speech context. Each child was tested in his/her native language on one native and one nonnative contrast. The nonnative contrast consisted of a real native word paired with a nonsense word containing a nonnative element. The native contrast consisted of a native word paired with a nonsense word containing a minimally paired native element. The results showed that both groups of children found identification of native contrasts much easier than identification of nonnative contrasts. The results suggest that by age 2, normal children may have achieved an awareness of their native phonology, an awareness that encourages them to ignore certain distinctions that are not part of their language's contrastive meaning system.

Child, Preschool↗

The perception of the sound of silence in early infancy.

When brief periods of silence are inserted between the /s/ and /lit/ portions of the English word "slit" (/slit/), adult listeners typically hear the word as "split" (/split/). 2 experiments were conducted to investigate the ability of 6-8-month-old infants to discriminate brief periods of interconsonantal silence in "slit" versus "split" contrasts. Infants were tested in multiple sessions, using a conditioned head-turning paradigm. 3 sets of stimuli were employed: /slIt/, /slIt/ +Silence, and /splIt/, containing 0, 173, and 90 msec, respectively, of silence duration following the /s/ portion of the stimulus. In both experiments, infants reliably discriminated /slIt/ +Silence from the /slIt/ stimuli but not from the /splIt/ stimuli. Therefore, it appears that infants, like adults, do not treat stimuli containing 90 or 173 msec of silence in this interconsonantal context as different.

Conditioning, Operant↗

Discrimination of voice onset time in infancy.

In an effort to determine whether infants can discriminate speech sounds on the basis of a single acoustic cue, timing onset of periodic voicing, two experiments were conducted employing synthetic speech sounds. Naturally produced syllable pairs were also used for comparison. In the first experiment infants evidenced discrimination of a naturally produced /ba/ versus /pa/ pair and a naturally /du/ versus /tu/ pair. In addition, infants discriminated a synthetic /ba/ versus /pa/ contrast that was cued by several acoustic differences in addition to timing onset of periodic voicing but failed to evidence an ability to discriminate a synthetic /du/ versus /tu/ contrast that contained flat first formants and differed only in timing onset of periodic voicing. A second experiment was conducted in which infants once again evidenced discrimination of naturally produced /du/ versus /tu/ stimuli but not of synthetic /du/ versus /tu/ stimuli containing slight first-formant transitions. These results suggest that timing onset of periodic voicing alone may not be a sufficient cue for infant discrimination of English voicing contrasts.

Acoustic Stimulation↗

A comparative study of speech perception in young severely retarded children and normally developing infants.

The discrimination of minimally paired speech sounds by seven retarded children with a mean age of 3 years, 2 months and a mean IQ of 38.4 was compared with the discrimination performance of eight normally developing 7-month-old infants. Children and infants were tested using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm in which they were taught to respond with a head turn to a change in a repeating background auditory stimulus. Responses were reinforced by activation of an animated toy. All children proved to be conditionable and both groups evidenced discrimination of the speech contrasts tested. The data suggest that the retarded children have moree difficulty processing a contrast cued by rapid spectral changes (often associated with consonant discrimination) than they do a contrast cued by steady-state spectral information (often associated with the perception of slowly articulated vowels). The normally developing infants did not find rapid spectral cues mor difficult than steady-state cues These results parallel those of Tallal (1976) who found that dynamic cues were specifically difficult for dysphasic children (with normal nonverbal intelligence), but not for linguistically-normal elementary school children.

Child, Preschool↗

Effects of early linguistic experience on speech discrimination by infants: a reply.

This paper is a reply to a critique of Eilers, Gavin, and Wilson (1979) by Aslin and Pisoni (this issue). The reply argues that the critics' contentions are basically unwarranted on both methodological and conceptual grounds. The critique is largely based on misunderstandings of the study's purposes and procedures.

Discrimination Learning↗

Linguistic experience and phonemic perception in infancy: a crosslinguistic study.

English- and Spanish-learning infants were tested for perception of 2 synthetic speech contrasts differing in voice onset time. The 2 pairs were chosen so that they were native to either Spanish or English. Using the Visually Reinforced Infant Speech Discrimination (VRISD) paradigm, 6--8-month-old infants were taught to respond to a change in auditory stimuli with a headturn. Correct headturns were reinforced by the activation of a lighted animated toy. While Spanish-learning infants provided evidence of discriminating both English and Spanish contrasts, English-learning infants only provided evidence of discriminating their native contrast. The results are discussed in terms of the role of linguistic experience in the development of speech perception skills in infancy.

Cross-Cultural Comparison↗

Developmental changes in speech discrimination in infants.

A visually reinforced infant speech discrimination (VRISD) paradigm is described and evaluated. Infants at two ages were tested with the new paradigm on the following speech contrasts: [sa] vs [va], [sa] vs [fa], [sa] VS [za], [as] vs [a:s], vs [a:z], [at] vs [a:d], [a:t] vs [a:d], [at] vs [a:t], [fa] vs [thetaa]and [fi] vs [thetai]. The data reported are compared with data on the same speech contrasts obtained from three month olds in a high-amplitude sucking paradigm. Evidence suggesting developmental changes in speech-sound discriminatory ability is reported. Results are interpreted in light of salience of available acoustic cues and in terms of new methodological advances.

Age Factors↗

Fricative discrimination in early infancy.

In three separate experiments using controlled natural stimuli and a high-amplitude sucking paradigm, infants' ability to detect differences between /s/ and /v/, /s/ and /f/, and /s/ and /z/, respectively, was investigated. Evidence for discrimination was obtained for /s/ versus /v/ and /s/ versus /f/ but not for /s/ versus /z/. Implications for a theory of infant speech perception are discussed.

Age Factors↗

Precursors to speech in infancy: the prediction of speech and language disorders.

During the canonical stage of infant babbling, infants produce well-formed syllables, often in reduplicated sequences such as "bababa." Although nearly all infants with normal hearing begin the canonical stage by 10 months of age, a few are delayed, and these infants may be of special interest. Recent studies indicate that late onset of canonical babbling may be a predictor of disorders. A simple screening procedure that focuses on canonical babbling was used to evaluate over 3400 infants at risk who were about 10 months of age. Among infants who showed late onset of canonical babbling, fewer than half had been previously diagnosed as having a significant medical problem that might have accounted for the delay. A follow-up study indicated that infants with delayed canonical babbling had smaller production vocabularies at 18, 24, and 30 months than did infants in the control group. The results suggest that late onset of canonical babbling, a factor that can be monitored effectively through an interview with a parent, can predict delay in the onset of speech production.

Age Factors↗