Acoustic characteristics of Arabic pharyngealized obstruents in children with cochlear implants.

Speech production of children with cochlear implants (CIs) is generally characterized by low intelligibility and reduced phoneme accuracy. However, limited research investigated their speech production using acoustic measures. The current study examined voice onset time (VOT) for pharyngealized plosives [t,d], and spectral moments and noise duration for pharyngealized fricatives [s,ð] produced by Arabic speaking children with CIs. Productions from children with CIs were compared with both chronological age-matched and hearing experience-matched normal hearing children. Results showed that children with CIs exhibited difficulty producing distinct VOTs between plosives and produced different spectral patterns of both fricatives relative to both comparison groups; however, they were able to produce an acoustic distinction between both fricatives. Children with CIs produced the fricatives with lower spectral mean and higher skewness and kurtosis. The sources for inter-group differences in the acoustic measures appeared to be due in part to limitations in the quality of auditory input provided by CIs as well as reduced motor experience in speech production. Results suggest that VOT and spectral moments are sensitive to changes in perceived sound quality. Spectral moments analysis appears to give details on subtle aspects of fricative production at the phonetic level beyond that available using perceptual judgments.

Predicting the Future: A Case Study in Prognostication.

PURPOSE: Clinicians are regularly asked to make long-term prognoses. The aim of the current report was to present one systematic approach to doing so. A case example from a malpractice case involving a child fitted with a cochlear implant was presented. Implantation occurred at age 17 months (activation 1 month later), but due to a procedural error, the implant was not functional for 19 months. The problem was ultimately rectified, but the legal case hinged largely on whether the child would be able to make up for the lost time. METHOD: A review of the literature on long-term outcomes in children with cochlear implants was conducted. Using 4 studies measuring outcomes 7-10 years later, outcomes were compared between children implanted at age 17-18 months and those implanted at age 36-37 months. RESULTS: Analysis suggested no potential impact on nonverbal cognitive skills. However, analysis in the areas of speech perception, word comprehension, speech intelligibility, and reading suggested that after 7-10 years, this child would potentially continue to be approximately 1-2 years behind where she might otherwise have been. CONCLUSIONS: This case illustrated the possibility of deriving a long-term prognosis using a systematic examination of the existing outcomes literature. Such an approach is consistent with our mandate to engage in evidence-based practice.

Emergence and Prevalence of Persistent and Residual Speech Errors.

This report reviews the existing literature on the emergence and prevalence of speech sound errors in older children and adults. Findings from several different sources suggest that 1 to 2% of the young adult population overall may present with these errors. Up to 75% of these errors may resolve on their own between the end of the developmental period (i.e., age 9 years) and the end of high school, though speech therapy services may still be justified to reduce any negative social consequences of these errors. At least two different sources of these errors are postulated. Residual speech errors (the more common of the two types) appear to arise as a leftovers from a much earlier speech delay and were originally omission or substitution errors but migrated closer to normal to become distortions. Persistent speech errors, on the other hand, appear to be distortions from an early age that reflect long-instantiated habits. Whether this distinction points to different responses to particular interventions, or whether either type is more or less likely to resolve spontaneously is not clear at this time.

Psychometric characteristics of single-word tests of children's speech sound production.

PURPOSE: Our understanding of test construction has improved since the now-classic review by McCauley and Swisher (1984). The current review article examines the psychometric characteristics of current single-word tests of speech sound production in an attempt to determine whether our tests have improved since then. It also provides a resource that clinicians may use to help them make test selection decisions for their particular client populations. METHOD: Ten tests published since 1990 were reviewed to determine whether they met the 10 criteria set out by McCauley and Swisher (1984), as well as 7 additional criteria. RESULTS: All of the tests reviewed met at least 3 of McCauley and Swisher's (1984) original criteria, and 9 of 10 tests met at least 5 of them. Most of the tests met some of the additional criteria as well. CONCLUSIONS: The state of the art for single-word tests of speech sound production in children appears to have improved in the last 30 years. There remains, however, room for improvement.

Effectiveness of systematic articulation training program accessing computers (SATPAC) approach to remediate dentalized and interdental /s, z/: a preliminary study.

Traditional methods for treating speech distortion errors in older school-age children have tended to yield mixed success. The current study was a preliminary evaluation of an alternative approach called the Systematic Articulation Training Program Accessing Computers (SATPAC), which was tested for the remediation of /s/ and /z/. Procedures involved a sequence of phonetic placement and/or oral-motor placement cues as needed to establish the targets, followed by concentrated drill structured around a facilitating context nonsense word and then advanced to more natural contexts. Participants were 18 children aged 6 years, 9 months to 11 years, 10 months. Treatment involved once per week, individual, 10-min. sessions with an experienced speech-language pathologist. Group A (n = 9) received 15 weeks of treatment, while treatment was delayed for Group B (n = 9). Then the groups were reversed. During period one, Group A (treated) significantly improved their accuracy of /s, z/ in spontaneous speech, while Group B (untreated) showed no significant change. During period two, Group B improved significantly when treatment was applied. The majority of the participants retained proficiency two years later.

Reference data for the American English acoustic vowel space.

Reference data for the acoustic vowel space area (VSA) in children and adolescents do not currently appear to be available in a form suitable for normative comparisons. In the current study, individual speaker formant data for the four corner vowels of American English (/i, u, æ, ɑ/) were used to compute individual speaker VSAs. The sample included 300 children aged 5-18 years and 38 adults aged 25-50 years. Age trends and sex differences were examined and reference data for clinical application were developed. Findings indicated significant declines in VSA with age; sex differences were not fully apparent until late adolescence and adulthood. Implications are discussed.

Single word and sentence intelligibility in children with cochlear implants.

This study examined the intelligibility of speech produced by 17 children (aged 4-11 years) with cochlear implants. Stimulus items included sentences from the Beginners' Intelligibility Test (BIT) and words from the Children Speech Intelligibility Measure (CSIM). Naïve listeners responded by writing sentences heard or with two types of responses to the word recordings; open transcription (CSIM-T) and closed set multiple choice (CSIM-MC). Percentage of items understood, averaged across three naïve judges, were compared across the three measures. Additionally, scores were examined for any relationships with chronological age, age of implantation, and amount of implant experience. Strong positive correlations were observed among all three intelligibility tasks. Scores on all three tasks were found to be significantly different from each other. A significant correlation was obtained between intelligibility and amount of implant experience, but not with chronological age or age of implantation. Results suggest that judging the intelligibility of speech produced by children with cochlear implants using both single word and sentence levels would provide a better overall estimate of their intelligibility. The results also emphasize the vital role of auditory input in the development of intelligible speech.

Ear selection and pediatric cochlear implants: a preliminary examination of speech production outcomes.

OBJECTIVE: The goal of the current study was to examine whether ear selection (left versus right) for cochlear implantation results in significant differences in speech production outcomes. METHODS: Ten children with right-ear implants were compared to five children with left-ear implants on intelligibility of speech produced in single words, sentences, and conversation as well as on accuracy of speech sounds produced during administration of a single word articulation test and in conversational speech. RESULTS: The children with right-ear implants performed significantly better than those with left-ear implants but only on the single word tasks. No significant differences were observed at the sentence or conversational speech levels. CONCLUSION: Findings are discussed relative to the possibility that the obtained ear of implantation differences (if real) may disappear over time. Such a conclusion is quite tentative however given the small sample size in the current study. Such a limitation may also explain why no differences were obtained for the connected speech measures. Further study of ear selection outcomes is clearly indicated.

Intelligibility of spontaneous conversational speech produced by children with cochlear implants: a review.

OBJECTIVE: The emergence of cochlear implant technology has raised hopes about improved outcomes for children with severe and profound hearing impairments. This study sought to examine the current literature to help evaluate whether the new technology is living up to its promise specifically relative to the intelligibility of conversational speech produced by these children. METHOD: At least 20 studies to date have reported findings for the intelligibility of speech produced by children fitted with cochlear implants. The current review involved a descriptive, summary examination of 10 of these studies that analyzed spontaneous conversational speech. RESULTS: The review suggested that intelligibility outcomes for these children appear to be considerably better than we have historically seen in this population (i.e., prior to the development of cochlear implant technology). For children implanted very early it appears that progress toward intelligible speech is more rapid, and the development of fully intelligible speech may be a reasonable goal for many such children. Even for children implanted somewhat later, progress on speech intelligibility appears to continue for at least 10 years post-implantation. CONCLUSION: It would appear that cochlear implants are providing much better outcomes compared to older intervention approaches, at least relative to the intelligibility of spontaneous conversation.

Phonological patterns in the conversational speech of children with cochlear implants.

UNLABELLED: In this descriptive, longitudinal study, phonological patterns (i.e., natural phonological processes) were examined in a set of conversational speech samples obtained from six young children fitted with cochlear implants. Both developmental and non-developmental patterns were observed. This is consistent with findings from previous studies of the speech of children with hearing loss who wear hearing aids. Several of the patterns found were also the same as those reported in previous studies of children with cochlear implants. One developmental pattern and two non-developmental patterns were significantly correlated with age demonstrating a decrease over time. Trends were evident in several other patterns suggesting possible directions for future investigations. LEARNING OUTCOMES: The reader will be able to (1) differentiate developmental from non-developmental phonological patterns, (2) identify the patterns that can be seen in the speech of children fitted with cochlear implants, and (3) understand the direction of pattern occurrence over time in this population.

Prosody and voice characteristics of children with cochlear implants.

This descriptive, longitudinal study involved the analysis of the prosody and voice characteristics of conversational speech produced by six young children with severe to profound hearing impairments who had been fitted with cochlear implants. A total of 40 samples were analyzed using the Prosody-Voice Screening Profile (PVSP; Shriberg, L. D., Kwiatkowski, J., & Rasmussen, C. (1990). Prosody-Voice Screening Profile (PVSP). Tuscon, AZ: Communication Skill Builders). Overall, the children presented with noticeable problems with stress and resonance quality. There were some difficulties noted with rate, loudness, and laryngeal quality, but there were no consistent difficulties with phrasing or pitch. This suggested that prosody and voice characteristics in this population are different from those typically observed in children with severe to profound hearing impairments though some problem areas remain. Some developmental trends were also observed. These findings suggest that cochlear implants offer some significant benefits to children with hearing impairment in terms of prosody and voice outcomes.

Syllables per word in typical and delayed speech acquisition.

A number of authors have presented data on the word length (measured in syllables) in the spontaneous speech of children across the developmental period. These data suggest a developmental trend of increasing length with age. The current study sought to examine this possibility in more detail. Conversational speech data from 320 children with normal (or normalized) speech confirmed that the number of syllables per word in conversational speech increases significantly from age 3-8 years. Data from the conversational speech of 202 children with speech delay however showed no such trend. Reasons for the differences between the two groups are discussed.

Measuring the intelligibility of conversational speech in children.

Conversational speech is the most socially-valid context for evaluating speech intelligibility, but it is not routinely examined. This may be because it is difficult to reliably count the number of words in the unintelligible portions of the sample. In this study four different approaches to dealing with this problem are examined. Each is based on the assumption that it is possible to perceive syllables in unintelligible strings even when the target words are unknown; these unintelligible syllables can then be used to estimate the number of unintelligible words in these samples using at least four different approaches. Preliminary data are presented for each of the four approaches based on conversational speech from two convenience samples including 320 children with normal (or normalized) speech and 202 children with speech delay. Differences among the four approaches are discussed.

Intelligibility of conversational speech produced by children with cochlear implants.

UNLABELLED: The intelligibility of conversational speech produced by six children fitted with cochlear implants before age 3 years was measured longitudinally. Samples were obtained every 3 months during periods of 12-21 months. Intelligibility was measured using both an utterance-by-utterance approach and an approach to the sample as a whole. Statistically significant differences were observed between the two approaches, but the differences were all within the realm of measurement error. Findings indicated that intelligible speech emerges quite rapidly in these children. Conversational intelligibility appears to be superior to that reported in the literature for similar children who use hearing aids but not necessarily as good as in children with normal hearing. Both intelligibility measures were significantly correlated with chronological age, hearing age, and amount of implant use, but were most strongly correlated with chronological age. LEARNING OUTCOMES: The reader will be able to (1) describe some of the issues involved in measuring speech intelligibility in children with cochlear implants and (2) describe the pattern of outcomes for the intelligibility of speech produced by children receiving cochlear implants before age 3 years.

Measuring severity of involvement in speech delay: segmental and whole-word measures.

PURPOSE: This study examined whether any of a series of segmental and whole-word measures of articulatory competence captured more of the variance in impressionistic ratings of severity of involvement in speech delay. It also examined whether knowing the age of the child affected severity ratings. METHOD: Ten very experienced speech-language pathologists rated severity of involvement from conversational speech samples obtained from 17 children with delayed speech. The ratings were then correlated with the candidate measures. The ratings by those who knew the ages of the children were also compared with the ratings by those who did not. RESULTS: The severity ratings showed considerable variability. Ratings from 6 clinicians who largely agreed with each other (a "tin standard" group) were significantly associated with several of the candidate measures. Clinicians appeared to pay attention to number, type, and consistency of errors when rating severity. They also attended to both segmental and whole-word levels. Knowledge of the children's ages did not appear to affect the ratings. CONCLUSIONS: The observed variability in the severity ratings raises significant questions about their usefulness. Objective measures such as some of those examined herein offer potential as more valid and reliable severity indexes.

Articulation rate and speech-sound normalization failure.

Not all children with speech delay (SD) of unknown origin develop fully normal speech even with intervention. Many retain residual distortion errors into adolescence and ultimately into adulthood. The current study examined whether articulation rate distinguishes those children who retain residual errors from those who normalize. Two groups of speech-delayed children originally identified at preschool age were retested at age 9 years (the early follow-up group) and at age 12-16 years (the late follow-up group), respectively. No differences in articulation rate were observed at either test time in conversational speech between those children who continued to produce residual distortion errors (RE) compared to those children who had fully normalized speech (NSA). For the late follow-up group, children in the RE outcome group articulated speech at significantly slower rates than the children in the NSA outcome group in an embedded words task using both syllables per second and phones per second measures. Findings suggested that children with SD of unknown origin who fail to normalize may have relative speech-motor deficits and possibly deficits in language formulation skill. Alternatively, slower articulation rate in structured tasks may represent some sort of compensation for the continuing presence of speech-sound errors. Possible motivations for such compensation are discussed.

A diagnostic marker for speech delay associated with otitis media with effusion: the intelligibility-speech gap.

The goal of this study was to determine if notably reduced intelligibility is a potential diagnostic marker for children with speech delay and histories of early recurrent otitis media with effusion (SD-OME). Intelligibility was assessed in one 5-10 minute conversational speech sample from each of 281 speakers. The OME histories of 148 of these children with normal speech acquisition were described in two prior reports. OME histories of 85 additional children with speech delay were obtained from case history reports. For both groups, the children with positive OME (OME+) histories had significantly lower intelligibility scores but significantly higher speech production scores than children with negative OME (OME-) histories. Findings for a diagnostic marker to discriminate speech delayed children with OME+ versus OME- histories were promising, considering that the data were obtained retrospectively and did not include audiological information characterizing children's concurrent fluctuant hearing loss. The formula for the diagnostic marker, termed the Intelligibility-Speech Gap, was identified by a machine learning routine. Diagnostic accuracy findings for the marker were as follows: positive predictive value = 74%, negative predictive value = 86%, sensitivity = 79%, specificity = 83%, positive likelihood ratio = 4.6 and negative likelihood ratio = 0.25. Discussion considers speech processing perspectives on the source of the intelligibility-speech gap in children with suspected SD-OME, and methodological perspectives on its development as a diagnostic marker of one etiological subtype of speech delay.

Acoustic phenotypes for speech-genetics studies: toward an acoustic marker for residual /s/ distortions.

Findings in a prior study series indicate that acoustic markers may have the requisite sensitivity and specificity to discriminate speakers with histories of several types of speech disorders, one of which is posited to be genetically inherited. The present study in this series compares acoustic data from three groups of adolescent speakers. Group 1 speakers had residual dentalized /s/ distortions in conversational speech and histories of significant age-inappropriate deletion and substitution errors. Group 2 speakers also had residual dentalized /s/ distortions in conversational speech, but their speech histories were limited to dentalized distortions of /s/ and other fricatives/affricates. Group 3 speakers had typical speech on assessment and no histories of speech errors. Owing to the limited number of perceptually dentalized /s/ tokens produced by Groups 1 and 2 speakers in a phrase-level speech task, acoustic analyses were completed on /s/ tokens transcribed as correct for speakers in all groups. Moments analyses of /s/ spectra in three words with /s/-initial clusters yielded statistically significant differences and consistent trends for mean spectral frequency and spectral variance for Group 1 compared with Group 2 speakers. These findings for perceptually normal /s/ tokens are interpreted as additional support for the potential of acoustic markers to discriminate speakers' speech-error histories. The discussion considers possible developmental and normalization correlates of the acoustic findings for speakers with each of the two types of speech-error histories studied in this paper.

Longitudinal changes in articulation rate and phonetic phrase length in children with speech delay.

This study examined long-term changes in articulation rate (the pace at which speech segments are produced) and phonetic phrase length in the conversational speech of two groups of children with speech delay (SD) of unknown origin. Initial testing for both groups occurred at preschool age, with follow-up testing conducted for the Early Follow-Up Group (n = 17) at age 9 years and for the Late Follow-Up Group (n = 36) at age 12-16 years. At follow-up testing both groups produced significantly faster articulation rates (measured in both syllables per second and phones per second) and significantly longer phonetic phrases (measured in both syllables and phones) than at initial testing. Articulation rates at both test times were also judged to be similar to published values from typically developing children of similar ages when measured in syllables per second. However, findings for rate in phones per second suggested that at least at initial testing the children were articulating speech at a slower rate than their typically developing peers. This latter finding, however, may have been an artifact of the high frequency of errors--such as cluster reduction and final consonant deletion--observed in the initial samples. It would appear, therefore, that children with SD of unknown origin may start out with slower than normal articulation rates but eventually catch up to their typically developing peers.