Steven B. Chin

Consonant Clusters in Disordered Speech: Constraints and Correspondence Patterns.

Comparison of patterns of cluster realization from 47 children ranging in age from 3;4 to 6;8 with functional (non-organic) speech disorders with those reported in the literature for normal acquisition reveals that these patterns are essentially the same for both groups. Using a two-level generative phonology for childrens independent systems, further analysis of cluster realizations by means of feature geometry and underspecification theory reveals that there are systematic and principled relationships between adult representations of clusters and childrens underlying representations and between childrens underlying representations and their phonetic representations. With special emphasis on coalescence phenomena, it is suggested that the apparent diversity in childrens cluster realizations can be reduced to four constraints on the form of underlying and phonetic representations.

A phonological system at 2 years after cochlear implantation

This report is a description of a developing phonological system as manifested in the productions of a prelingually deafened child approximately 2 years after fitting with a Nucleus 22-Channel Multi-Electrode Cochlear Implant. A probe list consisting of 23 proper nouns familiar to the child was used to elicit samples of her speech; stimulus materials consisted of photographs of those persons (friends and family members) whose names were included in the probe list. Analysis of the childs productions addressed the composition of the phonetic inventory of consonants and vowels and the presence of syllable structure and other phonotactic constraints. Results indicated a rich inventory of speech sound segments (among both consonants and vowels) and a lack of stringent constraints on syllable structure and consonants permitted in specified word positions. A further comparative analysis of correspondences with the ambient language showed a number of patterns that are also common in the speech of children with normal hearing.This report is a description of a developing phonological system as manifested in the productions of a prelingually deafened child approximately 2 years after fitting with a Nucleus 22-Channel Multi-Electrode Cochlear Implant. A probe list consisting of 23 proper nouns familiar to the child was used to elicit samples of her speech; stimulus materials consisted of photographs of those persons (friends and family members) whose names were included in the probe list. Analysis of the childs productions addressed the composition of the phonetic inventory of consonants and vowels and the presence of syllable structure and other phonotactic constraints. Results indicated a rich inventory of speech sound segments (among both consonants and vowels) and a lack of stringent constraints on syllable structure and consonants permitted in specified word positions. A further comparative analysis of correspondences with the ambient language showed a number of patterns that are also common in the speech of children with normal hearing.

Alcohol and Speech

Introduction The Nature and Pharmacology of Alcohol Speech Production and Speech Acoustics Research Methodology Research Review I: 1915-1964 Research Review II: 1966-1982 Research Review III: 1985-1996 Case Study: The U.S. Tankship Exxon Valdez and Novel Scientific Evidence Conclusions Appendices Glossary References Index.

The effects of age at implantation on speech intelligibility in pediatric cochlear implant users: Clinical outcomes and sensitive periods

This study assessed the effects of age at implantation on the speech intelligibility of congenitally, profoundly deaf pediatric cochlear implant users. The children received implants during the first eight years of life and were divided into subgroups based on their age at implantation. The childrens tape recordings of standard sentences were digitized and played back to normal-hearing listeners who were unfamiliar with deaf speech. Intelligibility was measured as the number of words correctly identified averaged across all listeners. The data showed that earlier implantation had a positive and significant effect on the speech intelligibility of cochlear implant users. The results also suggested that a gradual decline in the ability to acquire spoken language skills may occur over time and, furthermore, cochlear implantation before the age of two years may yield significantly better speech intelligibility outcomes than later implantation.

The ear is connected to the brain: some new directions in the study of children with cochlear implants at Indiana University.

Since the early 1980s, the DeVault Otologic Research Laboratory at the Indiana University School of Medicine has been on the forefront of research on speech and language outcomes in children with cochlear implants. This paper highlights work over the last decade that has moved beyond collecting speech and language outcome measures to focus more on investigating the underlying cognitive, social, and linguistic skills that predict speech and language outcomes. This recent work reflects our growing appreciation that early auditory deprivation can affect more than hearing and speech perception. The new directions include research on attention to speech, word learning, phonological development, social development, and neurocognitive processes. We have also expanded our subject populations to include infants and children with additional disabilities.

Relationships among types of speech intelligibility in pediatric users of cochlear implants

UNLABELLED Twenty pediatric users of cochlear implants were administered three tests of speech intelligibility: (1) a test of contrast perception intelligibility, (2) a test of contrast production intelligibility, and (3) a test of production sentence intelligibility. Sixty adults with normal hearing served as listener judges for the two speech production tasks, and percent correct scores were generated for each of the three tasks. Correlational analyses showed significant correlations among overall scores for the three tasks. However, scores for individual feature classes from the contrast perception task were not correlated with their corresponding contrast production feature class scores, and only some of the feature class scores were correlated significantly with sentence intelligibility. We conclude that although these three types of intelligibility are related at a gross level, relationships are more tenuous at finer levels of analysis, suggesting that the separate skills may need to be addressed separately in remediation. EDUCATIONAL OBJECTIVES As a result of this activity, the participant will be able to differentiate various methods for assessing speech intelligibility and describe the relationships among different types of speech intelligibility in pediatric users of cochlear implants.

Phonological Distance Measures

Abstract Phonological distance can be measured computationally using formally specified algorithms. This work investigates two such measures, one developed by Nerbonne and Heeringa (1997) based on Levenshtein distance (Levenshtein, 1965) and the other an adaptation of Dunnings (1994) language classifier that uses maximum likelihood distance. These two measures are compared against naïve transcriptions of the speech of paediatric cochlear implant users. The new measure, maximum likelihood distance, correlates highly with Levenshtein distance and naïve transcriptions; results from this corpus are easier to obtain since cochlear implant speech has a lower intelligibility than the usually high intelligibility of the speech of a different dialect.

Realization of Complex Onsets by Pediatric Users of Cochlear Implants.

This study examined variations in English complex onset realizations by children who use cochlear implants. Data consisted of 227 productions of two‐segment onset clusters from 12 children. In general, onset cluster realizations of children with cochlear implants did not differ markedly from those reported for children with normal hearing: null realizations were rare or nonexistent, there were few epenthetic realizations, one‐segment realizations generally respected sonority principles, and two‐segment realizations reflected singleton constraints. Further examination also revealed that the basis for variation among the children with cochlear implants could be attributed to differences in constraint rankings within Optimality Theory. Differences in constraint rankings could thus account for variations in the number of output segments, in the role of sonority in reduction, and in relationships between segmental and featural faithfulness.

Fortition and Lenition Patterns in the Acquisition of Obstruents by Children with Cochlear Implants.

This paper investigates patterns of error production in 10 children who use cochlear implants, focusing specifically on the acquisition of obstruents. Two broad patterns of production errors are investigated, fortition (or strengthening) errors and lenition (or weakening) errors. It is proposed that fortition error patterns tend to be related to the process of phonological development, because they are involved with universal implications and notions of markedness. Lenition error patterns, on the other hand, show more context‐sensitive effects and reflect properties related to minimization of articulatory effort. The relationship between fortition and markedness is demonstrated in an optimality theoretic analysis, and it is further demonstrated that the observed characteristics of phonological development in children with cochlear implants are similar to those exhibited by children with normal hearing.

Structure of mental lexicons of children who use cochlear implants: Preliminary findings

Logan1 has proposed that children older than 2 years with normal hearing organize and retrieve words from their mental lexicons using a phoneme-based strategy similar to that of adults. It is not clear whether the mental lexicons of children with profound deafness who use cochlear implants (CIs) are similarly organized, but the structures of such lexicons may indicate how these children acquire the ability to recognize and produce spoken words. To examine this, errors produced by such children on the Lexical Neighborhood Test (LNT),2 an open-set, monosyllabic word recognition test, were analyzed within the framework of the Neighborhood Activation Model (NAM).3,4 This model proposes that spoken word recognition occurs in the context of phonologically similar words, such that recognition of a spoken word is dependent on 1) the frequency of occurrence of the word and 2) words in the lexicon that are phonologically similar (by single-phoneme substitution, addition, or deletion) to the target word (“neighbors”), including both the number of neighbors (“neighborhood density”) and the neighbors’ mean frequency of occurrence in the language (“neighborhood frequency”).