Singleton Consonants Research Articles

An Acoustic Analysis of Singleton and Geminate Emphatic and Non-Emphatic Consonants in Arabic

Differences in length between singleton and geminate consonants with the same feature have received considerable attention in the literature. However, little work has been done to analyze differences in duration between singleton and geminate consonants with distinct features. This acoustic study sought to examine the differences in duration between singleton and geminate emphatic and non-emphatic consonants in Standard Arabic. The target consonants consisted of emphatic /sˤ/, /tˤ/, and /ðˤ/ (in singleton and geminate form) and their non-emphatic counterparts: /s/, /t/, and /ð/ (in singleton and geminate form). The stimuli consisted of 12 words, six of which contained a singleton and the other six of which contained a geminate, in order to test the closure/friction duration of those sounds. Seven native-speaking Arabic students from Prince Sattam bin Abdulaziz University were recruited as participants for the study. They were recorded while producing the target words containing intervocalic singleton and geminate consonants in a carrier phrase. The results generally showed a large singleton-to-geminate ratio difference in closure/friction duration. The singleton-to-geminate ratios showed that a geminate consonant was approximately twice the duration of a singleton. However, the results showed no difference between the ratios and means of emphatic and non-emphatic singleton consonants or between the closure/friction durations of emphatic and non-emphatic geminate consonants.

Gemination and Degemination before the Feminine Sound Plural Suffix in Native and Loanwords in Arabic

This study aimed to explore the gemination of consonants preceding the Feminine Plural suffix /-a:t/ in native and loanwords in Arabic, which consonants are geminated and when they are degeminated before /a:t/, to compare the conditions under which geminated and ungeminated consonants occur before /a:t/; and to define the relationship between the vowels preceding geminate and singleton consonants in syllables before /a:t/. A sample of 70 loanwords and 70 native Arabic nouns and/or adjectives having a Feminine Sound Plural (FSP) form with geminated and degeminated consonants before the suffix /a:t/ was collected from some websites. Data analysis showed that the FSP formation of both native and loanwords in Arabic follows the same Arabic pluralization rules. When a stem ends in a singleton consonant, the feminine plural suffix /a:t/ is directly added in لمسات /lamasa:t/ touches & درونات /dro:na:t/ drones. Almost all types of consonants can be geminated in word-final position in Arabic. In this case, the suffix /a:t/ is directly added to form FSP as in فلزّات /filizza:t/ metals & لمات /lamma:t/ gatherings. But when the stem ends with a vowel following the geminated consonant, the vowel is deleted as Arabic does not allow the sequence of two vowels (مودات /mawadda:t/ affections). The stops /p, b, k, g/, fricatives /f, ʃ, tʃ, dʒ/ and graphemes {ll}; {lla}, {ette} are geminated in some loan stems before the plural suffix /a:t/ as in كليبات /klippa:t/ clips; تريلات /trilla+a:t/ trailers; بروفات /proof+a:t/ professors; تاتشات /tatʃtʃ+a:t/ touches; مانشيتات /manʃitt+a:t/ manchettes (headlines). In 48% of the loanwords in the sample, the final consonant of the stem is not geminated before /a:t/ ماركت) /ma:rkita:t/ markets( due to the long vowel in a preceding syllable. In loanwords where the stem is feminine singular ending in /a/, this vowel is deleted before /a:t/ as in صالات /Sala:t/ salles; كاميرات /kamira:t/ cameras, as it is the case in native Arabic words with stems ending in /a/. No gemination takes place before /a:t/ as there is a long vowel in a preceding syllable. The study concludes with recommendation for language and translation pedagogy and for future research.

The impact of the Speech Systems Approach on intelligibility for children with cerebral palsy: a secondary analysis

Background The motor speech disorder, dysarthria, is common in cerebral palsy. The Speech Systems Approach therapy programme, which focuses on controlling breath supply and speech rate, has increased children’s intelligibility. Objective To ascertain if increased intelligibility is due to better differentiation of the articulation of individual consonants in words spoken in isolation and in connected speech. Design Secondary analysis. Setting University. Participants Forty-two children with cerebral palsy and dysarthria aged 5–18 years, Gross Motor Function Classification System I–V. Intervention The Speech Systems Approach is a motor learning therapy delivered to individuals by a speech and language therapist in 40-minute sessions, three times per week for 6 weeks. Intervention focuses on production of a strong, clear voice and speaking at a steady rate. Practice changes from single words to increasingly longer utterances in tasks with increasing cognitive load. Main outcome measures Unfamiliar listeners’ identification of singleton consonants (e.g. nap) and clusters of consonants (e.g. stair, end) at the start and end of words when hearing single words in forced choice tasks and connected speech in free transcription tasks. Acoustic measures of sound intensity and duration. Data sources Data collected at 1-week pre- and 1-week post-therapy from three studies: two interrupted time series design, one feasibility randomised controlled trial. Results Word initial and word final singleton consonants and consonant clusters were better identified post-therapy. The extent of improvement differed across word initial and word final singleton consonant subtypes. Improvement was greater for single words than connected speech. Change in sound identification varied across children, particularly in connected speech. Sound intensity and duration increases also were inconsistent. Limitations The small sample size did not allow for analysis of cerebral palsy type. Acoustic data were not available for all children, limiting the strength of conclusions that can be drawn. The different but phonetically balanced word lists, used in the original research, created variability in single words spoken across recordings analysed. Low frequencies of plosives, fricatives and affricates necessitated their combination for analysis preventing investigation of the effect of specific consonants. Connected speech was spontaneous, again creating variability within the data analysed. The estimated effects of therapy may therefore be partially explained by differences in the spoken language elicited. Conclusions The Speech Systems Approach helped children generate greater breath supply and a steady rate, leading to increased intensity and duration of consonant sounds in single words, thereby aiding their identification by listeners. Transfer of the motor behaviour to connected speech was inconsistent. Future work Refining the Speech Systems Approach to focus on connected speech early in the intervention. Personalisation of cues according to perceptual and acoustic speech measures. Creation of a battery of measures that can be repeated across children and multiple recordings. Study registration This trial is registered as Research Registry 6117. Funding This project was funded by the National Institute for Health and Care Research (NIHR) Efficacy and Mechanism Evaluation programme (NIHR130967) and will be published in full in Efficacy and Mechanism Evaluation; Vol. 10, No. 4. See the NIHR Journals Library website for further project information.

The production of English syllable-level timing patterns by bilingual English- and Spanish-speaking children with cochlear implants and their peers with normal hearing

We examined the timing parameters in syllables of English containing word initial singleton sonorants (/l/ and /ɹ/) and stop+sonorant clusters by bilingual English- and Spanish-speaking children with cochlear implants (CImp group) and their cohorts with normal hearing (NH group). The timing parameters included: voice onset time (henceforth, VOT), vowel duration following word initial singleton consonants and vowels following word initial stop+sonorant clusters as well as lateral and rhotic duration in word initial position and in stop+sonorant clusters. Our motivation for the current study was to address whether hearing loss affects the production of the timing parameters of syllables and whether language interference in bilingual productions is modulated by hearing loss. The results of the English production tasks show effects of onset type (singleton, C, vs complex onsets, CC) on VOT, whereby VOT for word initial singleton stops was shorter than VOT in stop+sonorant clusters. To the contrary vowel duration tended to extend temporally as more consonants are added to the onset. With regard to lateral and rhotic duration in word initial singleton and complex onsets, both groups (CImp and NH) showed the typical compression effect of /l/ in complex onsets characteristic of the timing pattern for sonorants in English complex syllables, though no shortening of the rhotic was found for the NH group. Combined results suggest little effect of hearing loss on the production of the timing parameters of English syllables, and virtually no effects across groups that can be attributed to language interference.

Mandarin Chinese-speaking learners’ acquisition of Italian consonant length contrast

The acquisition of Italian consonant length contrast by Mandarin Chinese-speaking learners (henceforth Chinese learners) has hardly been investigated. This study aims to fill this gap. Ten first-year, ten second-year and ten third-year Chinese undergraduate students majoring in Italian and ten native Italian-speaking controls took part in a perception and a production experiment. In the perception experiment, the participants had to identify ten Italian disyllabic minimal pairs contrasting in consonant length. In the production experiment, the participants were asked to read five out of the ten minimal pairs mentioned above; the duration values of the intervocalic consonants and the preconsonantal vowels were measured and converted into duration ratios for statistical analyses. The results show that, in both perception and production, Chinese learners can distinguish between the two consonant length categories in Italian to a certain extent, but not in a native-like manner. Also, the duration interplay between Italian consonants and preconsonantal vowels (i.e., longer vowels before singleton consonants and shorter vowels before geminate consonants) is entirely ignored by Chinese learners. Moreover, Chinese learners’ increased learning experience does not appear to enhance their acquisition of Italian consonant length contrast. Some pedagogical implications are discussed.

Word structure and consonant interaction in a French-speaking child with protracted phonological development

ABSTRACT This paper presents data from a Québec French-speaking child with protracted phonological development (PPD) who received phonological intervention based on a nonlinear phonological framework. At 5;3, he showed relative strengths in word structure compared with consonants (e.g., /s, f, v, k, ɡ/). Addressing segmental constraints in intervention led to higher overall accuracy and more consistent production of singleton consonants and word-medial consonant sequences and further gains in word structure. As part of a special cross-linguistic issue on individual profiles in PPD, the current paper provides an in-depth pre/post-treatment phonological analysis and contributes to emerging normative French-Canadian data on assessment and treatment.

English-Malay speech acquisition by children with Indian (Tamil) heritage

ABSTRACT Speech acquisition by Indian children is under-explored. This study investigates English-Malay speech acquisition by forty children (2;06-4; 05) of the third largest ethnic group (Indian) in Malaysia, a multi-ethnic multilingual country. The multilingual model and multilingual phonological test proposed by (Lim, Wells, & Howard, [2015] Rate of multilingual phonological acquisition: Evidence from a cross-sectional study of English-mandarin-malay. Clinical Linguistics and Phonetics, 29(11), 793–811; Lim [2018] Multilingual English-Mandarin-Malay phonological error patterns: The multilingual model and multilingual phonological test proposed in the initial cross-sectional study of 2 to 4 years old Malaysian Chinese children. Clinical Linguistics and Phonetics, 32(10), 889–912.) were used in the present assessment and analysis of child speech data. Two versions of the multilingual phonological test (English and Malay) were administered to the children. The age of phoneme acquisition and phonological patterns were analysed. The children showed comparable phonological milestones with children of other ethnic heritages acquiring the same languages. All singleton consonants were acquired by 4;06. All except one consonant cluster (/dɹ/) were acquired by 4; 06, indicating earlier acquisition than the local Chinese children in the past study. All vowels were acquired by 2; 11 and vowel phonological patterns were rare. There was a decrease with age in the use of consonant phonological patterns. Some consonant phonological patterns were shared by both languages (e.g., fronting), others were used in one language only (e.g., English cluster reduction) implicating the influences of language universalities and ambient language characteristics. Only age and language dominance factors, but not sex factor were found to have influenced the English-Malay speech acquisition. The extra exposure to Tamil by some children (38%) might have accelerated the acquisition of English clusters since Tamil shares clusters with English. The present findings contribute both clinical information to speech-language therapists and theoretical knowledge to the current literature of child phonology.

Icelandic Children's Acquisition of Consonants and Consonant Clusters.

Purpose This study investigated Icelandic-speaking children's acquisition of singleton consonants and consonant clusters. Method Participants were 437 typically developing children aged 2;6-7;11 (years;months) acquiring Icelandic as their first language. Single-word speech samples of the 47 single consonants and 45 consonant clusters were collected using Málhljóðapróf ÞM (ÞM's Test of Speech Sound Disorders). Results Percentage of consonants correct for children aged 2;6-2;11 was 73.12 (SD = 13.33) and increased to 98.55 (SD = 3.24) for children aged 7;0-7;11. Overall, singleton consonants were more likely to be accurate than consonant clusters. The earliest consonants to be acquired were /m, n, p, t, j, h/ in word-initial position and /f, l/ within words. The last consonants to be acquired were /x, r, r̥, s, θ, n̥/, and consonant clusters in word-initial /sv-, stl-, str-, skr-, θr-/, within-word /-ðr-, -tl-/, and word-final /-kl̥, -xt/ contexts. Within-word phonemes were more often accurate than those in word-initial position, with word-final position the least accurate. Accuracy of production was significantly related to increasing age, but not sex. Conclusions This is the first comprehensive study of consonants and consonant cluster acquisition by typically developing Icelandic-speaking children. The findings align with trends for other Germanic languages; however, there are notable language-specific differences of clinical importance.

Simplification of syllable structure in childhood apraxia of speech: a 2-year follow-up French case study

ABSTRACT Although Childhood Apraxia of Speech (CAS) has been extensively investigated in the clinical literature, most of the findings regarding impairments in the production of syllable structure, recorded within this population, have been mainly focused on English. The main purpose of this two-year follow-up case study was, therefore, to examine whether syllable complexity may be considered as a robust indicator in CAS and whether it can explain the persistence of errors and, if so, at what age. This was tested in a boy followed up annually from age 5 to 7 who was administered a narrative task. Data analyses used the Phon program to estimate accuracies of different syllabic structures, phones, singleton and cluster consonants. Overall, the findings suggest that this child experienced difficulty producing syllabic structure commensurately with the level of complexity of the target structures. Notably, the presence of syllable planning/sequencing deficit found in French data clearly supports the hypotheses according to which (a) there is a relationship between the level of complexity of syllabic structures and their simplification and (b) the persistence of errors on the most complex syllables remains, becoming a robust indicator for identifying CAS from other speech disorders. Further cross-language investigations on syllable complexity in CAS are needed to design better assessments and to plan efficient intervention.

Development of singleton consonants in French-speaking children with typical versus protracted phonological development: The influence of word length, word shape and stress

Purpose To provide preliminary reference data for singleton consonant development in children with typical development (TD) versus protracted phonological development (PPD) for Manitoba Canadian French, a language with an uncommon stress pattern (“iambic” or “right-headed”). Following a nonlinear perspective, singleton consonants were examined both as segments and in terms of the structure of words. Higher match levels for consonants were expected in shorter versus longer words and in stressed versus unstressed syllables. A larger effect was expected in children with PPD than those with TD. Method Participants included 20 TD children and 12 with PPD aged 2 to 4 years from Manitoba, Canada. Single words were digitally recorded by trained speech-language pathologists, transcribed by native French speakers and analysed with Phon 3.0. Result Friedman and Wilcoxon Signed Rank tests revealed that children with PPD had significantly more mismatches than TD children, especially in contexts of unstressed syllables in multisyllabic words. The most common mismatch (“error”) patterns were consonant substitution, consonant deletion and syllable deletion. Conclusion Word length and stress were found to influence consonant development within French, similar to findings in languages with left-headed or trochaic stress. Clinically, the findings underscore the relevance of considering the child’s entire phonological system for identification of strengths and needs in assessment and intervention.

Synchronic and diachronic strategies of mora preservation in Gújjolaay Eegimaa

The purpose of this study is to provide an overview of the synchronic and diachronic strategies that have led to the preservation of moraicity in noun and verb roots’ syllable structure among Gujjolaay Eegimaa (Bak, Atlantic, Niger-Congo) varieties spoken in southwestern Senegal. Two dialects, or varieties, of Eegimaa are geographically delineated along a peninsula of the Casamance River, locally known as The Kingdom. Cognate noun and verb roots between the two varieties differ phonemically on the basis of geminate consonants versus long vowels. Speakers of the more geographically isolated and conservative variety of Eegimaa use geminate consonants to the exclusion of long vowels, which are witnessed among speakers closer to the river’s borders. An otherwise productive process of lenition fails to apply in both instances: singleton consonants followed by long vowels that correspond with cognates with geminate consonants unexpectedly fail to weaken intervocalically. The under-application of lenition in the variety with long vowels leads to a postulation that geminates were the predecessor to long vowels in the Proto-language, yet no other attested Joola variety contains contrastive geminates. A comparison between the Eegimaa dialects and more-widely spoken Joola languages shows that nasal-voiceless plosive clusters are banned only in Eegimaa. Instead, cognates between Eegimaa and other Joola languages consistently display a geminate or a long vowel in place of an impermissible nasal-consonant cluster. The study appeals to mora preservation through both language contact and historical development as an explanation for the otherwise unusual appearance of geminates in the single Eegimaa variety as well as provides avenues for further research into multilingualism in Casamance, Senegal.

Contextual effects on the distinction of Japanese length contrasts in reverberation

Temporal structure in a word is crucial for understanding speech. In the distinction between Japanese singleton and geminate stops, listeners tended to perceive a consonant as geminate when the preceding vowel was longer [Ofuka et al., J. Phonetics Soc. Japan 9(2), 59–65 (2005)]. At the same time, listeners may not be able to use the contextual information in reverberation since the boundaries between each speech sound may become blurred by reverberation elongating and overlapping the sounds. The current study investigated whether the category boundary between singleton and geminate might change depending on duration of the preceding vowel in reverberation. Participants made a choice between singleton and geminate consonants embedded in an /a a/ context. The duration of the preceding vowel was changed. The experiments were conducted in a reverberant (RT = 2.6 s) and non-reverberant (RT = 0.1 s) condition. The results showed a significant shift in category boundary which indicated that listeners gave more “geminate” responses when the preceding vowel was longer, especially in the reverberant condition. The preceding vowel lengthened by reverberation caused listeners to choose “geminate.” Listeners might be more sensitive to the length of the adjacent phonemes for assessing the degree of reverberation.Temporal structure in a word is crucial for understanding speech. In the distinction between Japanese singleton and geminate stops, listeners tended to perceive a consonant as geminate when the preceding vowel was longer [Ofuka et al., J. Phonetics Soc. Japan 9(2), 59–65 (2005)]. At the same time, listeners may not be able to use the contextual information in reverberation since the boundaries between each speech sound may become blurred by reverberation elongating and overlapping the sounds. The current study investigated whether the category boundary between singleton and geminate might change depending on duration of the preceding vowel in reverberation. Participants made a choice between singleton and geminate consonants embedded in an /a a/ context. The duration of the preceding vowel was changed. The experiments were conducted in a reverberant (RT = 2.6 s) and non-reverberant (RT = 0.1 s) condition. The results showed a significant shift in category boundary which indicated that listeners gave more ...

Bilingual Speech Sound Development During the Preschool Years: The Role of Language Proficiency and Cross-Linguistic Relatedness.

The purpose of this study was to investigate typical Spanish-English speech sound development longitudinally in a group of bilingual preschoolers enrolled in a Head Start Program and to examine the extent to which such development is linked to language proficiency. The study also aimed to identify whether speech development is related cross-linguistically and to improve our understanding of error patterns in this population. Thirty-five bilingual preschool children produced single-word speech samples in Spanish and English both at the beginning of their first and their second year in a Head Start Program. Conversational samples in both languages were also collected at these data points to calculate mean length of utterance in words (MLUw) and thus assess the children's linguistic proficiency. The phonetically transcribed speech samples were compared over time in terms of segmental accuracy measures and error pattern frequencies. Correlation analyses were run to examine the relation between segmental accuracy measures across languages and between speech sound production and MLUw. One-way within-subject analysis of variance revealed significant improvements in accuracy over time in both languages, but not always for cross-linguistically unshared segments, nor for all consonant manner classes. Overall error rates decreased over time in both languages; although, certain error types showed no change. Cross-linguistic interactions were low in both languages. The results also revealed significant cross-linguistic correlations in segmental accuracy between Spanish and English, as well as between MLUw and speech sound production in both languages on a range of measures, with language-specific differences in Year 2 of the Head Start Program, but not in Year 1. This study is the first to document developmental changes in the speech patterns of Spanish-English bilingual preschool children over 1 year. Accuracy rates improved significantly in both languages, suggesting that enhanced exposure to the majority language at school may not impede phonological development in the home language. Bootstrapping effects were particularly pronounced on cross-linguistically shared sounds, which suggests that the same underlying skills are utilized in both languages, whereas language-specific singleton consonants and consonant clusters did not appear to benefit from exposure to the other language. The results also suggest an intricate link between phonological skills and morphosyntactic performance at the early stages of development, but a more complex pattern thereafter with differences that may be based on language-specific phonological properties.

Normative and validation data of an articulation test for Italian-speaking children

ObjectivesAs a standardized instrument to assess speech sound development in Italian-speaking children is currently lacking, norms used to diagnose speech sound disorders (SSD) are mainly based on studies including English-speaking participants. This application may result in misidentification of SSD due to linguistic differences. The aims of the study were to establish normative data on speech sound development of Italian-speaking children and to evaluate psychometric properties of Rossi's articulation test, the picture-naming test selected to assess speech sound development. MethodsA cross-sectional study including 694 normally-developing Italian-speaking children aged from 3 to 7 years was conducted. Children were administered Rossi's articulation test, and percentages of speech sound correct production were calculated. To evaluate inter-rater reliability of the test, audio-recordings of 50 children were scored by an additional examiner. The same rater scored the audio-recordings of 50 children twice with an interval of at least 1 week. To evaluate test-retest reliability, 144 participants were re-tested after 1-3 weeks by the same assessor. Scores were compared through Intraclass Correlation Coefficient (ICC). To assess construct validity, the developmental progression of total scores across age groups was verified by the estimation of the reference range for the test, using a regression procedure. ResultsAlmost all Italian children in the sample produced vowels and approximants correctly. Singleton consonants were acquired before consonant clusters. Ages of acquisition of each consonant were presented: plosives and nasals were early mastered by Italian children, while dental affricates, alveolar fricatives and the palatal lateral were the latest acquired segments. All ICCs were superior to 0.9 (reliability). A statistically significant improvement in test score with age was found (construct validity). ConclusionsThe paper provides normative data for speech sound development of Italian-speaking children; preliminary psychometric analysis of Rossi's articulation test revealed satisfactory reliability and construct validity. Clinicians are recommended to use Rossi's articulation test to assess speech sound development in Italian children.

Timing patterns of voiceless and voiced singleton and geminate plosives of Yanagawa Japanese

The paper examines acoustic timing patterns of word-medial voiceless and voiced singleton and geminate plosives of Yanagawa Japanese, one of the Chikugo varieties of Japanese spoken in the center of Kyushu (Japan). Unlike standard Tokyo Japanese, Yanagawa Japanese is characterized by frequent gemination of any types of consonants including voiced obstruents (e.g., /kuzzoko/ [kuddzoko] “sole, the fish,” /miroɡɡe/ [miɾoɡɡe] “a shell fish”). Five Yanagawa Japanese speakers were recorded. Another five speakers of standard Tokyo Japanese were also recorded as a control group. The stimuli consisted of nonsense words with C1V1C(C)2V2 structure (e.g., /kak(k)a/, /kaɡ(ɡ)a/). The findings suggest that the whole word duration containing geminate consonants was longer in proportion to mora count difference those containing singleton consonants, confirming moraic timing at word level in Yanagawa Japanese. When C2 was a geminate (voiceless or voiced), it lengthened the preceding vowel (V1) and shortened the following one (V2) in both dialects. However, the magnitude of influence of geminates to adjacent vowels was dialect specific: V1 duration in Yanagawa was consistently longer than Tokyo when the following consonant was a geminate. The results of the current study point towards the timing differences in singletons and geminates across Japanese dialects.

Describing Phonological Paraphasias in Three Variants of Primary Progressive Aphasia.

The purpose of this study was to describe the linguistic environment of phonological paraphasias in 3 variants of primary progressive aphasia (semantic, logopenic, and nonfluent) and to describe the profiles of paraphasia production for each of these variants. Discourse samples of 26 individuals diagnosed with primary progressive aphasia were investigated for phonological paraphasias using the criteria established for the Philadelphia Naming Test (Moss Rehabilitation Research Institute, 2013). Phonological paraphasias were coded for paraphasia type, part of speech of the target word, target word frequency, type of segment in error, word position of consonant errors, type of error, and degree of change in consonant errors. Eighteen individuals across the 3 variants produced phonological paraphasias. Most paraphasias were nonword, followed by formal, and then mixed, with errors primarily occurring on nouns and verbs, with relatively few on function words. Most errors were substitutions, followed by addition and deletion errors, and few sequencing errors. Errors were evenly distributed across vowels, consonant singletons, and clusters, with more errors occurring in initial and medial positions of words than in the final position of words. Most consonant errors consisted of only a single-feature change, with few 2- or 3-feature changes. Importantly, paraphasia productions by variant differed from these aggregate results, with unique production patterns for each variant. These results suggest that a system where paraphasias are coded as present versus absent may be insufficient to adequately distinguish between the 3 subtypes of PPA. The 3 variants demonstrate patterns that may be used to improve phenotyping and diagnostic sensitivity. These results should be integrated with recent findings on phonological processing and speech rate. Future research should attempt to replicate these results in a larger sample of participants with longer speech samples and varied elicitation tasks. https://doi.org/10.23641/asha.5558107.

Stimulus Characteristics of Single-Word Tests of Children's Speech Sound Production.

This clinical focus article provides readers with a description of the stimulus characteristics of 12 popular tests of speech sound production. Using significance testing and descriptive analyses, stimulus items were compared in terms of the number of opportunities for production of all consonant singletons, clusters, and rhotic and nonrhotic vowels of Standard American English; phonetic/phonological and structural complexity; and the presence of bound morphemes. The tests varied widely in terms of the number of opportunities for production of consonant singletons, clusters, and rhotic and nonrhotic vowels. Most of the tests included only 1 opportunity, scored or unscored, to produce a majority of the consonant singletons in each word position. Only 3 of the tests included stimulus items with 3-element clusters. The majority contained limited opportunities to produce 3- or 4-syllable stimulus items. The tests provided sufficient opportunities for production of most vowels, although most did not score vowels. The tests differed significantly in the complexity of their stimulus items. Most, however, contained a negligible number of items that, with the addition of a bound morpheme, resulted in a word-final cluster. Most of the tests elicit an inadequate sample with which to conduct a comprehensive phonological analysis.

Identification and Remediation of Phonological and Motor Errors in Acquired Sound Production Impairment.

This study aimed to test whether an approach to distinguishing errors arising in phonological processing from those arising in motor planning also predicts the extent to which repetition-based training can lead to improved production of difficult sound sequences. Four individuals with acquired speech production impairment who produced consonant cluster errors involving deletion were examined using a repetition task. We compared the acoustic details of productions with deletion errors in target consonant clusters to singleton consonants. Changes in accuracy over the course of the study were also compared. Two individuals produced deletion errors consistent with a phonological locus of the errors, and 2 individuals produced errors consistent with a motoric locus of the errors. The 2 individuals who made phonologically driven errors showed no change in performance on a repetition training task, whereas the 2 individuals with motoric errors improved in their production of both trained and untrained items. The results extend previous findings about a metric for identifying the source of sound production errors in individuals with both apraxia of speech and aphasia. In particular, this work may provide a tool for identifying predominant error types in individuals with complex deficits.

Effects of consonant voicing on vocalic segment duration across resonants and prosodic boundaries

Most languages, and especially English, reduce the duration of vocalic segments before voiceless obstruents relative to voiced ones. Previous studies examined this effect for final singleton consonants in tauto- and heterosyllabic contexts within a word. Here, monosyllabic words are examined for the effect both across resonants (e.g., “code”/”coat” vs. “cold”/”colt”) and across word boundaries and stress conditions (e.g., “no CODE”/”NO code” vs. “no GOAD”/”NO goad”). Preliminary results showed a typical effect for singleton stops, with vocalic segment reduced 33.6% for the voiceless stop. Vocalic segments were somewhat reduced with an intervening resonant (26.4%) but the resonance itself was more reduced (57.3%); vocalic segment and resonance were approximately the same duration as the vocalic segments alone in singleton syllables. The vocalic segment of “no” decreased slightly with following voiceless stop (8.2% when unstressed, 10.2% when stressed); this was smaller than other studies’ effect across syllable boundaries within words. The results indicate that the word and syllable structure impose timing effects of different magnitudes on both vowels and resonants due to voicing of an adjacent stop. It is surprising that the effect occurs across word boundaries and further that stress makes little difference. [Work supported by NIH grant DC-002717.]

What causes the greater perceived similarity of consonant-transposed nonwords?

Nonwords created by transposing two non-adjacent orthographic consonants (CONDISER) have been reported to produce more priming for their baseword (CONSIDER), and to be classified as a nonword less readily than nonwords created by transposing two orthographic vowels (CINSODER). We investigate the origin of this difference and its relevance for theories of letter position coding. In the unprimed versions of the lexical decision and same–different tasks, a consonant–vowel difference was found in the transposition condition, not when those letters are substituted (Experiment 1). We found that when transpositions involved the disruption of a consonant cluster (OPMITAL), reaction times were slowed compared to when transpositions involved only letters that are separated (CHOLOCATE; Experiment 2). As transpositions more frequently disrupt in consonant clusters than vowel clusters, this introduces a confound in studies investigating consonant and vowel transposition effects. Consistent with the idea that letter order is harder to resolve in clusters, the difference between consonants and vowels was eliminated when transpositions involve singleton consonants or vowels rather than those in clusters (Experiment 3). These results suggest that the precision of position coding does not differ between consonants and vowels, but that consonant–vowel status plays a role in structuring orthographic representations.