Vocal Development in Infants and Toddlers With Bilateral Cochlear Implants and Infants With Normal Hearing.

Purpose The purpose of this study was to investigate the time course of vocal development in infants and toddlers with bilateral cochlear implants (CIs; bilateral CI group) who are acquiring Finnish and to compare their progress to that of infants with normal hearing and typical development (TD group). Method Five thousand nine hundred sixty-four spontaneous utterances of 30 infants and toddlers (15 in both groups) were classified as either precanonical (PC) vocalizations, basic canonical syllables (BCS), or advanced forms (AF) levels. Time course of development and group differences were analyzed in a prospective longitudinal study during a time course of 1 year: before implantation and 1, 3, 6, 9, and 12 months after CI activation for the bilateral CI group and at 6, 9, and 12 months of age for the TD group. Results The least mature PC vocalizations decreased and the BCS and AF vocalizations increased for both the bilateral CI and TD groups during the follow-up period of 1 year. The bilateral CI group produced a lower percentage of PC vocalizations (effect size, ηp 2 = .35) and a higher percentage of BCS (effect size, ηp 2 = .16) and AF vocalizations (effect size, ηp 2 = 0.24) than the TD group. Conclusions The findings of this study showed that vocal development of infants and toddlers with early-identified profound hearing loss is delayed before CI activation. Findings also showed that infants and toddlers with bilateral CIs make rapid advancements in vocal development after implantation compared to infants with typical development. However, their vocal development seems to remain delayed at least during the 1st year of bilateral CI use as compared to the well-documented milestones of infants and toddlers with typical development. Information about the vocal development time course following bilateral CI activation helps parents recognize progress in auditory-guided speech development before the emergence and the use of spoken words in communication.

Grammatical Abilities in Young Cochlear Implant Recipients and Children With Normal Hearing Matched by Vocabulary Size.

Purpose: This study sought to expand understanding of the impact of cochlear implantation on grammatical acquisition by comparing young children who have vocabularies of comparable size. Two research questions were investigated: (a) Do young cochlear implant (CI) recipients have grammatical skills comparable to those of children with normal hearing (NH) matched by spoken vocabulary size? (b) Do these groups show associations between vocabulary size and grammatical measures? Method: The participants included 13 CI recipients at 24 months postactivation (chronological ages = 33-60 months; M = 44.62) and 13 children with NH between 27 and 30 months old (M = 20.69). The 2 groups were matched by their vocabulary size. Four grammatical outcomes were analyzed from the MacArthur Communicative Development Inventory (Fenson, Marchman, Thal, Dale, & Reznick, 2007) and 20-min language samples: (a) grammatical complexity, (b) mean length of utterances, (c) tense marker total, and (d) productivity scores. Results: The 2 groups showed comparable grammatical skills across the 4 measures. Consistently significant associations between vocabulary size and grammatical outcomes were found in the CI group, with fewer associations in the NH group. Conclusions: The 2 groups showed similar grammatical abilities. The young CI recipients appeared to be following a typical pattern of linguistic development.

Consonant Acquisition in Young Cochlear Implant Recipients and Their Typically Developing Peers.

PURPOSE: Consonant acquisition was examined in 13 young cochlear implant (CI) recipients and 11 typically developing (TD) children. METHOD: A longitudinal research design was implemented to determine the rate and nature of consonant acquisition during the first 2 years of robust hearing experience. Twenty-minute adult-child (typically a parent) interactions were video and audio recorded at 3-month intervals following implantation until 24 months of robust hearing experience was achieved. TD children were similarly recorded between 6 and 24 months of age. Consonants that were produced twice within a 50-utterance sample were considered "established" within a child's consonant inventory. RESULTS: Although the groups showed similar trajectories, the CI group produced larger consonant inventories than the TD group at each interval except for 21 and 24 months. A majority of children with CIs also showed more rapid acquisition of consonants and more diverse consonant inventories than TD children. CONCLUSIONS: These results suggest that early auditory deprivation does not significantly affect consonant acquisition for most CI recipients. Tracking early consonant development appears to be a useful way to assess the effectiveness of cochlear implantation in young recipients.

Can children substitute for adult listeners in judging the intelligibility of the speech of children who are deaf or hard of hearing?

PURPOSE: Assessments of the intelligibility of speech produced by children who are deaf or hard of hearing (D/HH) provide unique insights into functional speaking ability, readiness for mainstream classroom placements, and intervention effectiveness. The development of sentence lists for a wide age range of children and the advent of handheld digital recording devices have overcome two barriers to routine use of this tool. Yet, difficulties in recruiting adequate numbers of adults to judge speech samples continue to make routine assessment impractical. In response to this barrier, it has been proposed that children who are 9 years or older might be adequate substitutes for adult listener-judges (Ertmer, 2011). METHOD: To examine this possibility, 22 children from the 3rd, 4th, and 5th grades identified words from speech samples previously judged by adults. RESULTS: Children in the 3rd and 4th grades identified fewer words than adults, whereas scores for 5th graders were not significantly different from those of the adults. All grade levels showed increasing scores across low, mid, and high levels of intelligibility. CONCLUSIONS: Children who are functioning at a 5th grade level or higher can act as listener-judges in speech intelligibility assessments. Suggestions for implementing assessments and scoring child-listeners' written responses are discussed.

Relationships between vocalization forms and functions in infancy: preliminary implications for early communicative assessment and intervention.

PURPOSE: This preliminary study explored relationships between form and function in prelinguistic vocalizations to increase our understanding of early communicative development and to provide potential clinical implications for early communicative assessment and intervention. METHOD: Twenty typically developing infants-5 infants in each of 4 age groups, from 3 to 20 months of age-were included. Vocalizations from these infants had previously been categorized for their form (Nathani, Ertmer, & Stark, 2006) and function (Stark, Bernstein, & Demorest, 1993) characteristics. In the present study, cross-classification tabulations between form and function were conducted to examine relationships between vocalization types and their apparent uses. RESULTS: As anticipated, earlier developing forms were mostly associated with earlier developing functions, and later developing forms were mostly associated with later developing functions. However, there were some exceptions such that some forms were associated with a variety of functions, and vice versa. CONCLUSIONS: The results suggest that some forms are more tightly coupled to function than others in the prelinguistic and early linguistic period. Preliminary implications for developmental theory, future research, and clinical applications are discussed. Larger, longitudinal studies with typical and atypical populations and stricter methodological controls are needed to validate these findings.

Beginning to talk like an adult: increases in speech-like utterances in young cochlear implant recipients and typically developing children.

PURPOSE: Speech-like utterances containing rapidly combined consonants and vowels eventually dominate the prelinguistic and early word productions of typically developing (TD) toddlers. It seems reasonable to expect a similar phenomenon in young recipients of cochlear implants (CIs). The authors of this study sought to determine the number of months of robust hearing experience needed to achieve a majority of speech-like utterances in both of these groups. METHOD: Speech samples were recorded from CI recipients at 3-month intervals during the first 2 years of CI experience, and from TD children at time points between 6 and 24 months of age. Speech-like utterances were operationally defined as those belonging to the basic canonical syllables (BCS) or advanced forms (AF) levels of the Consolidated Stark Assessment of Early Vocal Development-Revised ( Ertmer, Young, & Nathani, 2007). RESULTS: On average, the CI group achieved a majority of speech-like utterances after 12 months of robust hearing experience and the TD group after 18 months. The CI group produced greater percentages of speech-like utterances at each interval until 24 months, when both groups approximated 80%. CONCLUSION: Auditory deprivation did not limit progress in vocal development as young CI recipients showed more-rapid-than-typical speech development during the first 2 years of device use. Implications for the infraphonological model of speech development are considered.

The development of falling intonation in young children with cochlear implants: a 2-year longitudinal study.

This article describes the development of intonation in 12 cochlear implant (CI) recipients. In a previously reported study of the first year of CI use, children who were implanted late (after 24 months) acquired intonation more rapidly than the younger participants. The older children's advantage is plausibly owing to their greater maturity. However, children who were implanted early (before 25 months) did not have an advantage over the still younger control group of infants with normal hearing (NH), suggesting that the advantage requires a critical age of about 30 months. The younger CI-users reached this age in the second year of CI use. The results confirmed our expectation that even the younger CI recipients would acquire intonation more rapidly than infants with NH who had the same amount of robust hearing experience. Clinical implications are discussed in relation to the question of early versus late implantation.

Consonant production accuracy in young cochlear implant recipients: developmental sound classes and word position effects.

PURPOSE: To compare young cochlear implant (CI) recipients' consonant production accuracy with that of age- and gender-matched peers who were typically developing (TD). In addition to examining initial consonants, the authors compiled new data regarding the accuracy of final consonants and the order of consonant acquisition. METHODS: Eleven young CI recipients with 24 months of CI experience and 11 age- and gender-matched TD peers produced target words in short sentences. Consonant production accuracy was examined for total scores, initial and final word positions, and three developmental sound classes: Early, Middle, and Late. RESULTS: Initial consonants were produced with relatively greater accuracy than were final consonants by the TD and CI groups. Whereas initial consonants appeared to be acquired in a typical order, descriptive data suggest that this might not be the case for final consonants. CONCLUSIONS: Although still delayed compared to age-matched peers, young CI recipients showed substantial progress in consonant acquisition. Their accuracy levels after 2 years of CI experience support the notion that implantation at a young age has added value for phonological development.

Monitoring progress in vocal development in young cochlear implant recipients: relationships between speech samples and scores from the Conditioned Assessment of Speech Production (CASP).

PURPOSE: To determine the concurrent validity of the Conditioned Assessment of Speech Production (CASP; Ertmer & Stoel-Gammon, 2008) and data obtained from speech samples recorded at the same intervals. METHOD: Nineteen children who are deaf who received cochlear implants before their 3rd birthdays participated in the study. Speech samples and CASP scores were gathered at 6, 12, 18, and 24 months postactivation. Correlation analyses were conducted to assess the concurrent validity of CASP scores and data from samples. RESULTS: CASP scores showed strong concurrent validity with scores from speech samples gathered across all recording sessions (6-24 months). CONCLUSIONS: The CASP was found to be a valid, reliable, and time-efficient tool for assessing progress in vocal development during young cochlear implant recipients' first 2 years of device experience.

Prelinguistic vocal development in young cochlear implant recipients and typically developing infants: year 1 of robust hearing experience.

This investigation examined the time course and sequence of prelinguistic vocal development during the first year of cochlear implant (CI) experience. Thirteen children who were implanted between 8 and 35 months and 11 typically developing (TD) infants participated in this longitudinal study. Adult-child play interactions were video- and audio-recorded at trimonthly intervals for each group, and child utterances were classified into categories representing progressively more mature productions: Precanonical Vocalizations, Basic Canonical Syllables, and Advanced Form vocalizations. Young CI recipients met the 20% criterion for establishment of the Basic Canonical Syllables and Advanced Forms levels with fewer months of robust hearing experience than the TD infants. Most CI recipients followed the sequence of development predicted by the Stark Assessment of Early Vocal Development-Revised. The relatively rapid progress of the CI children suggests that an earlier period of auditory deprivation did not have negative consequences for prelinguistic vocal development. It also supports the notion that young CI recipients comparatively advanced maturity facilitated expeditious auditory-guided speech development.

Children's development of intonation during the first year of cochlear implant experience.

This article describes the longitudinal development of intonation in 18 deaf children who received cochlear implants (CIs) before the age of 3 years and 12 infants with typical development (TD) who served as controls. At the time their implants were activated, the children with CIs ranged in age from 9 to 36 months. Cross-group comparisons were made when the children had equivalent amounts of robust hearing experience but different chronological ages. This article reports the results for the 6-month period ending 9 months after activation of the child's device for children with CIs, and the 6-month period ending at 12 months of age for TD infants. The findings were compared with a model of early intonation development in children with normal hearing. The results indicated that all groups progressed through one or more of the stages predicted by the normative model. At the end of the study period, however, children who had received a CI later than 24 months reached a more mature stage of intonation development than younger CI recipients. Moreover, the older CI group reached the same stage of development as the TD infants who had 3 additional months of language listening experience. The findings suggest that the developmental advantage which older children had previously demonstrated shortly after activation of their CIs is maintained throughout most or all of the first year of CI use.

Speech production accuracy and variability in young cochlear implant recipients: comparisons with typically developing age-peers.

PURPOSE: The speech production accuracy and variability scores of 6 young cochlear implant (CI) recipients with 2 years of device experience were compared with those of typically developing (TD) age-peers. METHOD: Words from the First Words Speech Test (FWST; Ertmer, 1999) were imitated 3 times to assess the accuracy and variability of initial consonants, vowels, and words. The initial consonants in the 4 sets of the FWST followed a typical order of development. RESULTS: The TD group produced targets with high accuracy and low variability. Their scores across FWST sets reflected the expected order of development. The CI group produced most targets less accurately and with more variability than the TD children. Relatively high accuracy for the consonants of Sets 1 and 2 indicated that these phonemes were acquired early and in a typical developmental order. A trend toward greater accuracy for Set 4 as compared with Set 3 suggested that later-emerging consonants were not acquired in the expected order. Variability was greatest for later-emerging initial consonants and whole words. DISCUSSION: Although considerable speech production proficiency was evident, age-level performance was not attained after 2 years of CI experience. Factors that might influence the order of consonant acquisition are discussed.

Assessing speech intelligibility in children with hearing loss: toward revitalizing a valuable clinical tool.

BACKGROUND: Newborn hearing screening, early intervention programs, and advancements in cochlear implant and hearing aid technology have greatly increased opportunities for children with hearing loss to become intelligible talkers. Optimizing speech intelligibility requires that progress be monitored closely. Although direct assessment of intelligibility has been a cumbersome undertaking, advancements in digital recording technology and expanded strategies for recruiting listener-judges can make this tool much more practical in contemporary school and clinical settings. PURPOSE: The main purposes of this tutorial are to present a rationale for assessing children's connected speech intelligibility, review important uses for intelligibility scores, and describe time-efficient ways to estimate how well children's connected speech can be understood. This information is offered to encourage routine assessment of connected speech intelligibility in preschool and school-age children with hearing loss.

Relationships between speech intelligibility and word articulation scores in children with hearing loss.

PURPOSE: This investigation sought to determine whether scores from a commonly used word-based articulation test are closely associated with speech intelligibility in children with hearing loss. If the scores are closely related, articulation testing results might be used to estimate intelligibility. If not, the importance of direct assessment of intelligibility is reinforced. METHOD: Forty-four children with hearing losses produced words from the Goldman Fristoe Test of Articulation-Second Edition (Goldman & Fristoe, 2000) and sets of 10 short sentences. Correlation analyses were conducted between scores for 7 word-based predictor variables and percent-intelligible scores derived from listener judgments of stimulus sentences. RESULTS: Six of 7 predictor variables were significantly correlated with percent-intelligible scores. However, regression analysis revealed that no single predictor variable or multivariable model accounted for more than 25% of the variability in intelligibility scores. CONCLUSIONS: The findings confirm the importance of assessing connected speech intelligibility directly.

Characteristics of the transition to spoken words in two young cochlear implant recipients.

PURPOSE: This investigation addressed two main questions: (a) How do toddlers' spoken utterances change during the first year of cochlear implant (CI) use? and (b) How do the time-courses for reaching spoken word milestones after implant activation compare with those reported for typically developing children? These questions were explored to increase understanding of early semantic development in children who receive CIs before their second birthdays. METHODS: Monthly recordings of mother-child interactions were gathered during the first year of CI use by a boy and a girl whose CIs were activated at 11 and 21 months of age, respectively. Child utterances were classified as nonwords, pre-words, single words, or word combinations, and the percentages of these utterance types were calculated for each month. Data were compared to published findings for typically developing children for the number of months of robust hearing (i.e., auditory access to conversational speech) needed to reach spoken word milestones and the chronological ages at which milestones were achieved. RESULTS: The main findings were that the percentages of nonwords and pre-words decreased as single words and word combinations increased. Both children achieved most spoken word milestones with fewer months of robust hearing experience than reported for typically developing children; the youngest recipient achieved more milestones within typical age ranges than the child implanted later in life. CONCLUSIONS: The children's expeditious gains in spoken word development appeared to be facilitated by interactions among their pre-implant hearing experiences; their relatively advanced physical, cognitive, and social maturity; participation in intervention programs; and the introduction of robust hearing within the Utterance Acquisition phase of language development according to the neurolingusitic theory (J. Locke, 1997).

El desarrollo vocal en niños sordos de familias hispanohablantes / Prelinguistic vocal development and children with hearing loss who are acquiring Spanish

El desarrollo vocal es un proceso que precede a la producción de las primeras palabras; durante este proceso el niño comienza a emitir sonidos cada vez más parecidos a los del adulto, aumentando poco apoco la complejidad de las sílabas, las palabras y la variedad de los sonidos. A pesar del interés clínico de este proceso, hasta la fecha pocos estudios han examinado el desarrollo vocal en bebés de familias hispanohablantes. Este artículo representa un esfuerzo por llenar ese vacío. En él el lector encontrará un análisis de los patrones típicos de desarrollo vocal en niños de diferentes contextos lingüísticos, con especial atención al caso de los niños que aprenden español. También se presenta un procedimiento para evaluar el desarrollo vocal mediante muestras espontáneas de producción y se describe una propuesta de intervención para niños con retraso en su desarrollo vocal. Los análisis y propuestas recogidos deben ser de interés para logopedas, audiólogos, maestros de sordos y terapeutas del lenguaje infantil en general. Los autores confían que este trabajo sirva de estímulo para abordar nuevas investigaciones sobre el desarrollo vocal de niños que familias hispanohablantes (AU)

Prelinguistic vocal development is the process by which children begin to produce increasingly complex, phonetically diverse, and speech-like utterances before theysay words on a regular basis. Despite its clinical interest, few studies have explored vocal development in very young children with hearing loss who are acquiring Spanish. This article represents an effort to fill this gap. In it, the reader will find a discussion of typical patterns of development in children from different language environments, with a special emphasis on Spanish. In addition, procedures for assessing vocal development through speech sampling and an intervention approach for children with delays in vocal development are presented. This information is intended to be of use for speech-language therapists, audiologists, and teachers of deaf children, and to encourage further research into the prelinguistic and early linguistic abilities of very young children with hearing losses who come from Spanish-speaking families (AU)

Profiles of vocal development in young cochlear implant recipients.

PURPOSE: The main purpose of this investigation was to examine the effects of cochlear implant experience on prelinguistic vocal development in young deaf children. Procedure A prospective longitudinal research design was used to document the sequence and time course of vocal development in 7 children who were implanted between 10 and 36 months of age. Speech samples were collected twice before implant activation and on a monthly basis thereafter for up to 2 years. Children's vocalizations were classified according to the levels of the Stark Assessment of Early Vocal Development--Revised (SAEVD-R; S. Nathani, D. J Ertmer, & R. E. Stark, 2006). RESULTS: The main findings were (a) 6 of 7 children made advancements in vocal development after implantation; (b) children implanted between 12 and 36 months progressed through SAEVD-R levels in the predicted sequence, whereas a child implanted at a younger age showed a different sequence; (c) milestones in vocal development were often achieved with fewer months of hearing experience than observed in typically developing infants and appeared to be influenced by age at implantation; and (d) in general, children implanted at younger ages completed vocal development at younger chronological ages than those implanted later in life. Specific indicators of benefit from implant use were also identified. CONCLUSION: The time course of vocal development in young cochlear implant recipients can provide clinically useful information for assessing the benefits of implant experience. Studies of postimplantation vocal development have the potential to inform theories of spoken language development.

Assessing vocal development in infants and toddlers.

The purpose of this study was to examine changes in prelinguistic vocal production during the first 20 months of life. Vocalizations were classified into 23 mutually exclusive and exhaustive types, and grouped into five ascending levels using the Stark Assessment of Early Vocal Development-Revised (SAEVD-R). Data from 30 typically developing infants, aged 0-20 months, show that older infants attained higher developmental levels on the SAEVD-R than younger infants. Infants 0-2, 3-5, and 6-8 months of age primarily produced vocalizations from Levels 1 (Reflexive), 2 (Control of Phonation), and 3 (Expansion). Infants 9-20 months of age also produced vocalizations from Level 4 (Basic Canonical Syllables). Only infants from 16-20 months of age produced Level 5 (Advanced Forms) vocalizations in significant quantities. The outcomes indicate that the SAEVD-R is a valuable instrument for evaluating prelinguistic vocal development.

How well can children recognize speech features in spectrograms? Comparisons by age and hearing status.

Real-time spectrographic displays (SDs) have been used in speech training for more than 30 years with adults and children who have severe and profound hearing impairments. Despite positive outcomes from treatment studies, concerns remain that the complex and abstract nature of spectrograms may make these speech training aids unsuitable for use with children. This investigation examined how well children with normal hearing sensitivity and children with impaired hearing can recognize spectrographic cues for vowels and consonants, and the ages at which these visual cues are distinguished. Sixty children (30 with normal hearing sensitivity, 30 with hearing impairments) in 3 age groups (6-7, 8-9, and 10-11 years) were familiarized with the spectrographic characteristics of selected vowels and consonants. The children were then tested on their ability to select a match for a model spectrogram from among 3 choices. Overall scores indicated that spectrographic cues were recognized with greater-than-chance accuracy by all age groups. Formant contrasts were recognized with greater accuracy than consonant manner contrasts. Children with normal hearing sensitivity and those with hearing impairment performed equally well.

Beginning to communicate after cochlear implantation: oral language development in a young child.

This longitudinal case study examined the emergence of a wide range of oral language skills in a deaf child whose cochlear implant was activated at 20 months. The main purposes of this study were to determine "Hannah's" rate of spoken language development during her second to fourth year of implant experience and to estimate the efficiency of her progress by comparing her performance to that of typically developing children. Mother-child interactions were also examined to determine changes in Hannah's communication competence. Normal or above-normal rates of development were observed in the following areas: (a) decreased production of nonwords, (b) increased receptive vocabulary, (c) type-token ratio, (d) regular use of word combinations, and (e) comprehension of phrases. Below-normal rates of development were observed in the following areas: (a) speech intelligibility, (b) number of word types and tokens, and (c) mean length of utterance in morphemes. Analysis of parent-child interactions showed a large increase in responses to questions during the third year of implant use. Data from Hannah's first post-implantation year (D. J. Ertmer & J. A. Mellon, 2001) indicated that some early language milestones were attained quite rapidly (e.g., canonical vocalizations and emergence of first word combinations). In contrast, the current study revealed that progress had slowed for related, but more advanced skills (e.g., production of intelligible speech and consistent use of word combinations). These changes in rate of development suggest that any advantages for language learning due to Hannah's advanced maturity (or other unknown factors) decreased with time and increasing linguistic complexity.