Phonological Mean Length Of Utterance Research Articles

Assessing the Phonological Abilities of Jordanian Arabic-speaking Children with Phonological Disorders

Objectives: This study investigated the validity of four language measures, i.e., phonological mean length of utterance (PMLU), the proportion of whole-word proximity (PWP), the proportion of whole-word correctness (PWC), and percentage of correct consonants, in assessing phonological development in Jordanian Arabic (JA) speaking children with phonological disorders in comparison with typically developing (TD) children.Methods: The study involved 88 monolingual JA-speaking children within the age range of 5 to 6 years, with 44 children diagnosed with phonological disorders and 44 TD children. Each group was further categorized into two age groups, namely 5;0-5;6 and 5,7-6,0. Data were gathered by observing the interactions between the children and their caregivers or parents using age-appropriate toys. A minimum of 100 utterances were collected from each participant.Results: The study found that TD children performed better than the children with phonological disorders on all measures, indicating delayed phonological performance in the phonological disorders group. Positive correlations between the measures were also observed, indicating their ability to provide significant information about children’s phonological abilities. Specific speech sound errors and substitution patterns exhibited by children with phonological disorders were identified, highlighting the motor control and articulatory challenges experienced by this group. Age was found to be a significant factor in the development of TD children, while children with phonological disorders showed similar scores across different age groups.Conclusion: These findings support the usage of the four measures for understanding phonological development in children with phonological disorders, accurately diagnosing them and tracking their progress.

Phonological Mean Length of Utterance in 48-60-Month-old Persian-Speaking Children With Isfahani Accent: Comparison of Story Generation and Conversation Samples

Objective Phonological Mean Length of Utterance (PMLU), a quantitative measure for assessing phonological skills, is a diagnostic and clinical criterion in phonological development. Moreover, it is an indicator showing the efficacy of the intervention. The PMLU is a word level measure that can be calculated on the child’s transcribed speech sample (transcription). To calculate PMLU, all consonants and vowels of the child’s produced words, and target words (standard production of words in native adults) are individually scored. The proportion of Whole-Word Proximity (PWP), another phonological quantitative measure, includes the ratio of the produced PMLU to the targeted word PMLU. PWP indirectly reflects the intelligibility of speech. Since languages are distinctive in syllabic and phonological structures, PMLU should be studied as a language-specific measure. PMLU has specifically been designed to assess phonological skills in spontaneous speech. Spontaneous speech sampling methods are advantageous since they consider the effect of morphological and syntactic skills, length, and complexity of words, and they could show the normal development of word complexity. This study was conducted to determine PMLU and PWP in 48 to 60 months old Persian-speaking children with Isfahani accents and to compare them in story generation and conversation sampling methods. The potential sensitivity of PMLU to growth was also examined. Materials & Methods This is an observational and cross-sectional study that was conducted for one year in 2016 in Isfahan City, Iran. A total of 100 children (51 boys and 49 girls) aged 48-60 months participated in story generation sampling, and 67 children (32 boys and 35 girls) participated in conversation sampling. The participants were selected from 261 kindergartens under the supervision of the Welfare Organization of Isfahan Province using the convenience sampling method. After completing the consent form and considering the inclusion criteria, conversation and story-generation samples were collected. Audio samplings were done in the same room using the same software (Clear Record Litev. 2.1). Raters transcribed the first 50 words of the recorded speech samples. Finally, we used the formula to calculate the target PMLU and child PMLU based on the normal production of an adult who speaks Persian with an Isfahani accent and the child’s production, respectively. To evaluate inter-rater reliability, raters randomly transcribed 20% of all samples to recalculate values. Participants’ story generation and conversation scores were entered into SPSS16 separately. The Kolmogorov-Smirnov test was used to examine the data distribution. Based on the data distribution, paired t-test and Wilcoxon test were used to compare measurements, and the Pearson and Spearman tests were used to investigate the associations. Results Child PMLU, target PMLU, and PWP measures of the story generation method were 8.794, 8.811, 0.998, and those of the conversation method were 9.068, 9.093, and 0.998, respectively. Correlation test results showed significant relationship between age and PWP in story generation (r=0.308) and conversation (r=0.313). Comparing child PMLU in story generation and conversation showed a significant relationship between child PMLU in both sampling methods (P=0.000). The result of the target PMLU comparison in two methods of story generation and conversation (P=0.000) was significant. PWP did not significantly differ between the two sampling methods (P=0.973). The inter-rater reliability was calculated at 0.70. Conclusion This study can be used as a basis for quantitative studies in the field of children’s phonological assessment using Persian whole words. However, longitudinal studies in different age groups with a high level of evidence in this field can convince therapists to use whole-word measures in clinics.

A comparison of two phonological screening tools for French-speaking children

Purpose: To examine two screening tools for phonological production, the Evaluation Sommaire de la Phonologie chez l’enfant d’âge préscolaire (ESPP) and the Test de Phonologie du Français Canadien-Dépistage (TPFC-D), developed according to differing theoretical perspectives. The TPFC-D, designed according to nonlinear phonology, includes more words and contains a greater variety of segments across word structure as compared to the ESPP, which was guided by a linear phonological framework. The greater response rate to test items, time of administration, and phonological complexity were expected on the TPFC-D. Method: Each screening tool was administered to 14 4-year-old French-speaking children living in Central Canada. Paired samples t-tests compared children’s responses on the two tasks with regards to (a) response rate and time of administration, (b) an overall percentage of consonants correct (PCC) and percentage of vowel correct (PVC), and (c) complexity of productions (i.e. PCC and PVC in relation to word structure, Word Shape Match, Whole Word Match, Phonological Mean Length of Utterance (pMLU) and Proportion of Whole-Word Proximity). Result: Item response rates were higher for the TPFC-D whereas time of administration, PCC and PVC were similar for both the ESPP and TPFC-D. Complexity measures showed a higher proportion of deletions in clusters and higher pMLUs on the TPFC-D compared to the ESPP. Conclusion: Both screening measures are appropriate for speech-language pathologists who want to assess quickly pre-school-aged children. Since the TPFC-D is phonologically more complex, it is recommended for clinicians needing to screen children who likely present with multiple speech sound errors across their phonological system.

Comparing Phonetic Complexity between Fluent and Disfluent Eojeols in Adults Who Stutter

Purpose: The purpose of this study was to investigate the characteristics of phonetic complexity in disfluent eojeols of adults who stutter. Therefore, phonetic complexity between fluent and disfluent [including stuttering-like disfluency (SLD) or other disfluency (OD)] eojeols was compared using two speaking tasks.Methods: Twenty-one adults who stutter performed a picture description task and a conversation task. Those speech samples were divided into eojeols, and each eojeol was classified as a “fluent eojeol” if it was perceptually fluent, an “OD eojeol” if it was produced with ODs, or an “SLD eojeol” if it was produced with SLDs. The index of phonetic complexity (IPC) and the phonological mean length of utterance (PMLU) were measured to compare phonetic complexity between the tasks and the types of eojeols.Results: The IPC was significantly the greatest in the SLD eojeol regardless of task. The IPC of the fluent eojeol was significantly greater than that of the OD eojeol. The SLD eojeol also showed significantly the greatest PMLU among the types of eojeols, and the fluent eojeol showed significantly greater PMLU than the OD eojeol. Significant positive correlations were found between IPCs and PMLUs for each eojeol no matter the task.Conclusion: When producing eojeols, greater phonetic complexity can trigger SLDs in adults who stutter, supporting the psycholinguistic aspects of stuttering.

How many words make a sample? Determining the minimum number of word tokens needed in connected speech samples for child speech assessment

ABSTRACT Connected speech (CS) is an important component of child speech assessment in both clinical practice and research. There is debate in the literature regarding what size sample of CS is required to facilitate reliable measures of speech output. The aim of this study was to identify the minimum number of word tokens required to obtain a reliable measure of CS across a range of measures. Participants were 776 5-year-olds from a longitudinal community population cohort study (Avon Longitudinal Study of Parents and Children, ALSPAC). Children’s narratives from a story retell task were audio-recorded and phonetically transcribed. Automatic analysis of the transcribed speech samples was completed using an automated transcription and analysis system. Measures of speech performance extracted included: a range of profiles of percentage consonant correct; frequency of substitutions, omissions, distortions and additions (SODA); percentage of syllable and stress pattern matches; and a measure of whole word complexity (Phonological Mean Length of Utterance, pMLU). Statistical analyses compared these measures at different CS sample sizes in increments using averages and weighted moving averages, and investigated how measures performed between CS samples grouped into word tokens of at least 50, 75 and 100, and restricted to samples of 50–74, 75–99 and 100–125. Key findings showed that sample sizes of 75 word tokens and above showed minimal differences in most measures of speech output, suggesting that the minimum requirement for samples of CS is a word count of 75. The exception to this is in the case of pMLU and measures of substitutions and distortions when a word count of 100 is recommended.

Whole-word measures and the speech production of typically developing Dutch children

ABSTRACTIn this study, the phonological whole-word measure Phonological Mean Length of Utterance was applied to identify stages in the phonological acquisition of Dutch children. Ninety spontaneous speech samples of 47 typically developing Dutch children from a previous study were examined. Samples were distributed across nine age groups ranging between 1;3–4;0 years. Across all age groups, PMLU of word productions increased significantly with the largest increase found below age 2;0 years. PMLU of the target words showed no significant increase across age groups. Outcomes suggest that the phonological whole-word measure PMLU can be further developed for clinical purposes in Dutch-speaking children. In the future, this measure could become relevant for the diagnosis and evaluation of therapy on the basis of spontaneous language.

Developing Weighted Phonological Mean Length of Utterance and Testing the Validity

배경 및 목적: 말소리 산출 능력을 정확하고 민감하게 반영할 수 있는 객관적 지표를 개발하고 타당성을 살펴보는 것은 중요하다. 본 연구에서는 가중평균음운길이라는 새로운 측정치를 제안하였으며, 일반아동과 말소리장애 아동의 말 자료를 토대로 자음정확도 및 평균음운길이와 비교하면서 가중평균음운길이의 타당도를 살펴보고자 하였다. 방법: 음절구조와 모음정확도,...

Towards automated detection of similarities and differences in bilingual speakers

Bilingualism is increasingly the norm in the United States with at least 20% of Americans being bilingual. This change in linguistic demography has created a new challenge to accurately diagnose speech disorders among bilingual children. This study explores Acoustic Landmark Detection (ALD) system as an objective approach to characterizing similarities and differences in speech production in child speakers of Standard English and Jamaican Creole (JC). Eight JC-English bilingual children were recorded speaking eleven words three times in each language. Words were transcribed and entered into PROPH + to provide: (1) Phonological Mean Length of Utterance [pMLU], (2) phonotactic structure, and (3) Percent Consonants Correct (PCC). Landmarks were hand-marked to determine probable landmark sequences based on canonical word production. Canonical landmark sequences were aligned with detected landmark sequences in both languages using the Needleman-Wunsch global alignment algorithm. Analysis revealed that if PCC indicates JC and English words are different, the mismatch between landmark tends to be lower (higher production accuracy); if phonotactics indicate JC and English words are different, mismatch tends to be slightly higher (lower accuracy); and if pMLU indicates word differences, mismatch tends to be higher (lower accuracy). Our finding support traditional linguistic expectations regarding bilingual speakers’ similarities and differences.

Speech Sound Development of Toddlers in Spontaneous Speech: Segmental Level and Whole Word Level Analysis

말소리 장애 유아의 평가와 중재를 위해서는 일반 유아의 말소리 발달 양상에 대한 정보가 필요하다. 본 연구는 일반 유아의 말소리 발달 양상을 분절음 단위와 단어 단위 지표를 사용하여 종단적으로 살펴보는 것을 목적으로 하였다. 2세 유아 3명, 3세 유아 2명을 대상으로 1년 6개월의 기간 동안 평균 6개월(5-8개월) 간격으로 총 4회, 자발화 맥락에서 분절음 단위 지표로 음소목록 유형 수, 총 자음 산출 수, 자음정확도(PCC)를 평가하였고, 단어 단위 지표로 단어단위복잡률(PMLU), 단어단위근접률(PWP), 단어단위정확률(PWC)로 평가하였다. 종단적으로 확인한 유아들의 말소리 발달에서 몇 가지 특성을 확인할 수 있었다. 3세 후반에서 4세 초반에는 지표의 증가율이 둔화되고 일부 지표는 천장효과가 나타나 이 시기에 유아들의 말소리 발달이 완성기에 들어서는 것으로 추정할 수 있었다. 그러나 일부 유아는 3세 전반에 이미 그러한 양상을 보여주어 개인차를 보여 주었다. 평가 지표에 따른 차이도 나타났는데, 분절음 단위의 PCC는 3세 후반에서 평균 95%(90.3∼97.1%)에 도달한 반면, 단어 단위의 PMLU는 5세까지 지속적으로 변화하였다. 또한 PCC가 집단 평균을 따라가는 것으로 나타난 일부 유아는 PMLU에서 집단 평균에 도달하지 못하였다. 이는 취학 전 유아의 말소리 발달 평가에서 분절음과 단어 단위 분석결과를 종합하여 사용할 필요성이 있음을 시사한다.This study aims to examine developmental characteristics of speech sounds in toddlers through segmental and whole word evaluation. Three toddlers of 2 years old and two toddlers of 3 years old participated in the study for the duration of one and a half years. Evaluations of spontaneous speech were performed four times with 6 month interval. Three indexes for segment level such as Number of Phonetic Inventory, Total Number of Consonants, and Percentage of Correct Consonant(PCC) and 3 indexes for whole word level such as Phonological Mean Length of Utterance(PMLU), Proportion of Whole-Word Proximity(PWP), and Proportion of Whole-word Correctness(PWC) were used for evaluation. The longitudinal study revealed several characteristics of speech sound development of participants. Around the time when toddlers reach the age of 4, each index started to increase at a slower pace with some demonstrating ceiling effect. These results suggest that the phonological development of toddlers entered stable stage at this said period. That said. however, there were individual differences for each child. There were differences regarding indexes as well. On average, PCC reached 95% at the later period of the age 3, whereas PMLU continued to change until the age of 5. Some toddlers whose PCC was in the normal developmental range showed PMLU lower than the group average. These results suggest that a comprehensive use of both segmental and whole word level analyses may be necessary in evaluating the phonological development of toddlers.

Entropy as a measure of mixedupness of realizations in child speech

AbstractTypical morpho-phonological measures of children’s speech realizations used in the literature depend linearly on their components. Examples are the proportion of consonants correct, the mean length of utterance and the phonological mean length of utterance. Because of their linear dependence on their components, these measures change in proportion to their component changes between speech realizations. However, there are instances in which variable speech realizations need to be differentiated better. Therefore, a measure which is more sensitive to its components than linear measures is needed. Here, entropy is proposed as such a measure. The sensitivity of entropy is compared analytically to that of linear measures, deriving ranges in component values inside which entropy is guaranteed to be more sensitive than the linear measures. The analysis is complemented by computing the entropy in two children’s English speech for different categories of word complexity and comparing its sensitivity to that of linear measures. One of the children is a bilingual typically developing child at age 3;0 and the other child is a monolingual child with speech sound disorders at age 5;11. The analysis and applications demonstrate the usefulness of the measure for evaluating speech realizations and its relative advantages over linear measures.

Evaluation of multisyllabic word production in Canadian English- or French-speaking children within a non-linear phonological framework

Currently, there is no theoretically justified, evidence-based metric for evaluating segmental and prosodic components of multisyllabic words (MSWs). A pilot study evaluated a MSW metric embedded in non-linear phonological- and language-processing frameworks. Six MSWs were analyzed in 10 Canadian English-speaking 5-year-olds with typically developing speech, and eight French-speaking children, ages 3–4 years, with protracted phonological development (PPD). Mismatches were tallied (with and without vowels), with totals ranked by word and participant, then compared with ranks from Phonological Mean Length of Utterance (PMLU) and Percent Consonants Correct (PCC) tallies. For both groups, the number of different ranks was significant in comparisons of MSW metrics with PMLU and PCC. Rank orderings were systematically higher for English-speaking children using the MSW metric, with/without vowels, and for French-speaking children using the MSW metric with vowels. Overall, the MSW metric was particularly suitable for fine-grained differentiation of phonological accuracy in MSW production.

Rethinking assessment measures of phonological development and their application in bilingual acquisition

This article discusses the measurements for phonological and prosodic development put forward in Ingram [Ingram, D. (2002). The measurement of whole-word productions. Journal of Child Language, 29, 713–733.], while at the same time expanding the crucial measures, phonological mean length of utterance (PMLU) and proportion of whole-word proximity (PWP). The goal of the expansion is to accommodate a wider set of phenomena, specifically those related to bilingual acquisition of languages with different categories (e.g. closed syllables in German and open syllables in Spanish). Data from three monolingual Spanish children and from three bilingual German--Spanish children are presented as illustration of the modified measurements: expanded PMLU of features (ePMLU-F), expanded PMLU of syllables (ePMLU-S) and expanded PWP (ePWP). By means of measuring both features and prosodic positions, the expanded measurements do better justice to the various aspects of child phonology. Nonetheless, an important goal of this article is to stimulate discussion in order to bring our state-of-the-art closer to descriptive adequacy.

Longitudinal changes in phonological whole-word measures in 2-year-olds

The purpose of this investigation was to describe changes in whole-word productions in the speech of children as they aged from 24 to 36 months. Spontaneous language samples were obtained from 12 participants during parent–child interactions every 3 months, beginning with each participant's second birthday. Fifty different words from each sample were analysed to determine changes in a variety of whole-word measures including phonological mean length of utterance (PMLU) for target words and words produced, proportion of whole-word proximity (PWP), and proportion of words produced correctly (PWC). Significant changes in whole-word measures were evidenced by the participants over the course of the investigation, and those scores did not show stabilization by the age of 36 months.

Phonological mean length of utterance in specific language impairment: a multi-case study of children acquiring Finnish

This study assesses the phonological development of four Finnish-speaking children (ages 4;8, 4;9, 4;9 and 5;5) with specific language impairment (SLI) and dyspractic features in speech. The analysis is performed using the phonological mean length of utterance (pMLU) method. Moreover, the children's phonological abilities are evaluated qualitatively in relation to segments, phonotactics and word structure. The results are compared with those obtained from four age-matched typically developing peers and with the data from an earlier study using the pMLU method on younger, typically developing Finnish children. In the pMLU analysis, the children with SLI performed roughly at the level of typically developing 2-year-old children. The qualitative analyses revealed that children with SLI had difficulties in producing word-medial clusters and word-initial consonants and that they exhibited frequent consonant assimilations, infrequent errors and vowel errors. The pMLU method did differentiate between children with SLI and typically developing children. However, qualitative analyses revealed some weaknesses of the pMLU method when assessing Finnish children with SLI.

The impact of bilingual language learning on whole-word complexity and segmental accuracy among children aged 18 and 36 months

This study investigates the phonological acquisition of 19 monolingual English children and 21 English–French bilingual children at 18 and 36 months. It contributes to the understanding of age-related changes to phonological complexity and to differences due to bilingual language development. In addition, preliminary normative data is presented for English children and English–French bilingual children. Five measures were targeted to represent a range of indices of phonological development: the phonological mean length of utterance (pMLU) of the adult target, the pMLU produced by the child, the proportion of whole-word proximity (PWP), proportion of consonants correct (PCC), and proportion of whole words correct (PWC). The measures of children's productions showed improvements from 18 to 36 months; however, the rate of change varied across the measures, with PWP improving faster, then PCC, and finally PWC. The results indicated that bilingual children can keep pace with their monolingual peers at both 18 months and 36 months of age, at least in their dominant language. Based on these findings, discrepancies with monolingual phonological development that one might observe in a bilingual child's non-dominant language could be explained by reduced exposure to the language rather than a general slower acquisition of phonology.

Phonological Mean Length of Utterance in Children with Phonological Disorders

Abstract Aim: Although phonological mean length of utterance (pMLU) is addressed in normal children as well as those with specific language impairment and cochlear implanted children, there is poor focus on children with phonological disorders. Hence, the present study was carried out to determine the pMLU in children with phonological disorders in comparison with typically developing Kannada-speaking children. Methods: The study followed a case control design. Clinical group comprised 16 individuals (14 males and 2 females) with phonological disorders in the age range of 3 to 6 years. The control group comprised 30 age-matched children of whom 15 were males and 15 were females. A minimum of 50 spontaneous speech utterances were elicited from each child for a duration of 30 to 40 minutes which was audio-recorded. The children's utterances were narrowly transcribed and pMLU was calculated for each child. The sum of each word in all the utterances were totaled and divided by the number of words produced by ...

Phonological development in very‐low‐birthweight children: an exploratory study

Very-low-birthweight (VLBW; birthweight<1500 g and/or gestational age <32 wks) children are at risk for speech problems. However, there are few studies on speech development in VLBW children at an early age. The aim of this study was to investigate phonological development in 2-year-old VLBW children. Twenty VLBW children without major neurosensory impairment (7 males, 13 females; mean birthweight 971 g, SD 315; mean gestational age 28 wks, SD 1.81) and 20 term children (7 males, 13 females; mean birthweight 3503 g, SD 416; mean gestational age 40 wks, SD 1.26) were compared on measures of phonological development derived from 20-minute spontaneous speech samples of standardized mother-child play interaction as well as on standardized tests of cognitive and psychomotor development, language, and behaviour. VLBW children had significantly fewer acquired consonants (median 9, p=0.02) and a significantly lower phonological mean length of utterance (pMLU; median 4.1, p<0.01) than term children (median acquired consonants 10, median pMLU 5.0). This study provides evidence for poor phonological development in even healthy VLBW children, compared with term-matched children, independent of their cognitive, psychomotor, and language development, and their behavioural functioning.

A comparison of two phonological assessment tools for monolingual Spanish-speaking children

This study compared two phonological assessment tools for use with young Spanish-speaking children in the American Southwest, FON and STAR. Each was administered to 27 1-, 2- and 3-year-old monolingual Spanish-speaking children in the greater Phoenix area. Analyses compared the children's rate of response, complexity of the children's productions, as measured by the Phonological Mean Length of Utterance (pMLU), and the proximities of the child's productions to the adult target words, as measured by the Proportion of Whole-Word Proximity (Proximity). Response rates increased with age, and were similar for both FON and STAR. Two-year-olds had higher pMLU scores on the STAR than the FON, but no difference was found for 3-year-olds. The children overall had significantly higher Proximity scores on the STAR words. Positive correlations between vocabulary size and phonological whole-word measures on both the FON and the STAR were found. Recommendations are that language sampling be used for children under age 2, the STAR word list for 2-year-olds, and either word list for 3-year-olds.

Whole word measures in bilingual children with speech sound disorders

Phonological acquisition traditionally has been measured using constructs that focus on segments rather than the whole words. Findings from recent research have suggested whole-word productions be evaluated using measures such as phonological mean length of utterance (pMLU) and the proportion of whole-word proximity (PWP). These measures have been investigated mainly in typically-developing children, but their use with children with speech sound disorders has been limited. This study compares PMLU, PWP, and consonant accuracy in Spanish–English bilinguals with speech sound disorders (SSD) to age-matched monolingual peers. This study relates directly to the type of research that Adele Miccio favoured. First, it is focusing on bilingual children. For the past 5 years, she has been the principal investigator of a grant developing a comprehensive phonological assessment tool for bilingual speakers. Second, during her career, Miccio advocated using multiple analyses to gauge the phonological skills of children, especially those with speech sound disorders. Her work in stimulability is evidence of that perspective. This study examines one ‘raditional’ measure (consonant accuracy) and two newer ones (pMLU and PWP), thereby broadening the analyses of phonological skills in bilingual children with SSD and thus carrying out multiple analyses, just as Miccio recommended throughout her illustrious career.

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