Acknowledgements

1. Normative Speech Accuracy Measures of Children 24 and 30 Months of Age Amanda Cox B.A., Marie Fillers B.S., Amanda Mershon B.S., and Nancy Scherer, Ph.D., CCC-SLP Department of Communicative Disorders, Speech-Language Pathology, East Tennessee State University, Johnson City, TN 37614 Abstract Results (cont) Discussion This study provided validation of the PCC-R performance curves developed by Campbell et al. at two age points under three years of age. This finding provides additional support for the use of the performance curves in interpreting speech accuracy measures during speech assessment of children under three years of age. While more data should continue to be collected to validate other age ranges, the performance curve appears to provide accurate normative guidelines for comparison of speech impairments that will be helpful for speech-language pathologists during their assessments of very young children. These norms may facilitate early identification of children with speech impairments and subsequent referrals for early intervention. Methods (cont) The purpose of this study was to compare Percentage of Consonants Correct-Revised (PCC-R) (Shriberg, Austin, Lewis, McSweeny & Wilson, 1997a) of typical 24- and 30-month olds to a performance curve developed by Campbell, Dollaghan, Janosky, and Adelson (2007). The sample included 28 typically developing children, 14 in the 24-month age group and 14 in the 30-month age group. A 100-utterence spontaneous speech sample was video recorded, transcribed phonetically, and analyzed for PCC-R and consonant inventory. Inter-rater transcription reliability for 17% of the sample was 90.5%. Consonant inventory and PCC-R scores were compared between the 24-month and 30-month age groups using t-tests. The consonant inventories and PCC-R scores were statistically larger at 30 months with p<0.05. The expansion in consonant inventories indicated that, by 24 months, nasals (e.g., m, n), glides (e.g., w, j), and stop consonants (e.g., p,b,t,d,k,g) have generally been mastered. By 30 months, the consonant inventory increased and consisted of primarily fricatives (e.g., f, s, z, sh) with an increase from 3.1 to 4.5 at 30 months of age. PCC-R scores from this study were then compared to the Campbell et al. performance curve using t-tests. The data collected in the present study were not statistically different from the Campbell et al. performance curves (24 months, df= 13, t = -1.5, p=0.15, and 30 months df = 13, t = -0.56, p=.59). The data in this study supports the validity of the performance curves at both 24 and 30 months of age. • Procedures • 3 theme-based toy sets were used to elicit 100 utterances containing a controlled number of consonants from each child • After each play session, the videotape was reviewed and glossed for word meaning then transcribed phonetically by two speech-language pathology graduate students at East Tennessee State University using the broad International Phonetic Alphabet (IPA) (Shriberg & Kent, 2003). • Inter-ratertranscription reliability on 17% of the sample was calculated to be 90.5%. Results Graph 4. Consonant Inventory of 24- Month Old Participants Graph 5. Consonant Inventory of 30- Month Old Participants Graphs 4 and 5 show independent data for consonant inventories for the comparison groups: 24 and 30 months of age. T-test comparison between the 24-month (M= 13.2, SD= 3.8) and 30- month (M= 17.5, SD= 2.8) groups indicate that the consonant inventories at 30 months were significantly higher than at 24 months (df=26, t= -3.5, p<0.05). Selected References Campbell, T.F., Dollaghan, C., Janosky, J.E., & Adelson, P.D. (2007). A performance curve for assessing change in percentage of consonants correct-revised (PCC-R). Journal of Speech, Language, and Hearing Research, 50 , 1100-1119. Shriberg, L.D. & Kent, R.D. (2003). Clinical Phonetics. Boston: Allynand Bacon. Shriberg, L. D., Lewis, B.A., McSweeny, J.L., & Wilson, D.L. (1997a). The percentage of consonants (PCC) metric: Extensions and reliability data. Journal of Speech, Language, and Hearing Research, 40, 708-722. Graph 1. PCC-R Scores for 24 Month Old Participants Graph 2. PCC-R Score for 30 Month Old Participants Graphs 1 and 2 show independent data of PCC-R scores for the comparison groups: 24 and 30 months of age. T-test comparison between the 24-months (M=66.2, SD=14.0) and 30-months (M=79.5, SD=12.9) groups indicate that the PCC-R scores were statistically significant (df=26, t= -2.6, p<0.05). Introduction The availability of normative guidelines for early speech development would assist clinicians in the assessment of young children. One measure of speech accuracy that has gained popularity is PCC-R; however, there is limited normative data for children under three years of age. Campbell et al. (2007) used a curve fitting approach to interpret PCC-R data from some existing studies, although the data at the early ages was limited. The purpose of this descriptive study was to compare PCC-R of typical 24- and 30-month olds to the performance curve developed by Campbell et al. Methods Participants • Twenty-eight children with typical development were separated into two groups: one group ranged in age from 24-25 months (7 male and 7 female) and the other group ranged in age from 29-31 months (8 male and 6 female). • Mean MLU scores for the 24-month age group was 1.8 (SD=0.57) and 2.5 (SD=0.61) for the 30-month age group • Parents/Guardians signed consent forms for each of the participants. Acknowledgements We would like to thank ETSU Little Bucs Child Care Center and the Child Study Center for their participation in this study. We would also like to acknowledge Brandon Phillips and LashondraPhillips for their assistance. Graph 3. Comparing PCC-R scores of the Current study with the Campbell et al. performance curve Table 1. Acquisition of Consonants by Manner Graph 3 shows the means and standard deviations of the 24- month age group in the current research (M=66.2, SD=14.0) and the Campbell et al. study (M=71.9, SD= 5.2). The means and standard deviations of the 30-month age group in the current research (M=79.5, SD=12.9) and the Campbell et al. study (M= 81.4, SD= 5.2) are also shown. T-test comparisons between the ETSU group and the performance curve indicated no statistical significance for either the 24-month age group (df= 13, t= -1.5, p>0.05) or for the 30-month age group ( df=13, t= -0.56, p>0.05). The ETSU group did show a greater variability than the comparison Campbell et al. data. The expansion in consonant inventories indicated that, by 24 months, nasals (e.g., m, n), glides (e.g., w, j), and stop consonants (e.g., p,b,t,d,k,g) have generally been mastered. By 30 months inventory increases consisted of primarily fricatives (e.g., f, s, z, sh) with an increase from 3.1 to 4.5 at 30 months of age.