Jane L. McSweeny

Extensions to the Speech Disorders Classification System (SDCS)

This report describes three extensions to a classification system for paediatric speech sound disorders termed the Speech Disorders Classification System (SDCS). Part I describes a classification extension to the SDCS to differentiate motor speech disorders from speech delay and to differentiate among three sub-types of motor speech disorders. Part II describes the Madison Speech Assessment Protocol (MSAP), an ∼ 2-hour battery of 25 measures that includes 15 speech tests and tasks. Part III describes the Competence, Precision, and Stability Analytics (CPSA) framework, a current set of ∼ 90 perceptual- and acoustic-based indices of speech, prosody, and voice used to quantify and classify sub-types of Speech Sound Disorders (SSD). A companion paper provides reliability estimates for the perceptual and acoustic data reduction methods used in the SDCS. The agreement estimates in the companion paper support the reliability of SDCS methods and illustrate the complementary roles of perceptual and acoustic methods in diagnostic analyses of SSD of unknown origin. Examples of research using the extensions to the SDCS described in the present report include diagnostic findings for a sample of youth with motor speech disorders associated with galactosemia, and a test of the hypothesis of apraxia of speech in a group of children with autism spectrum disorders. All SDCS methods and reference databases running in the PEPPER (Programs to Examine Phonetic and Phonologic Evaluation Records) environment will be disseminated without cost when complete.

A diagnostic marker for childhood apraxia of speech: the coefficient of variation ratio

Terms such as isochrony, syllable segregation, scanning speech and staccato‐like rhythmic quality have been used to characterize the temporal regularity that may be a core feature of apraxia of speech. The present report describes a procedure to quantify temporal regularity in children with suspected apraxia of speech (sAOS). Conversational speech samples from 15 such children, together with samples from 30 3–6‐year‐old children with normal speech acquisition and 30 3–6‐year‐old children with moderate to severe speech delay of unknown origin, were selected from an audio archive. Signal processing routines were developed to identify and measure the duration of speech and pause events in 24 utterances from the speech samples of each of the 75 speakers. A value termed the coefficient of variation expressed the normalized variability in the durations of each participants speech events and pause events within each utterance. A metric termed the coefficient of variation ratio, derived by dividing the coefficient of variation for pause events by the coefficient of variation for speech events, expressed a speakers relative temporal variation in the two domains. The 15 children with sAOS had higher coefficient of variation ratios than the 30 children in each of the two comparison groups, indicating that the children with sAOS had proportionally more variation in the duration of pause events and/or less variation in the duration of speech events. Findings are interpreted as supporting the view that a constraint in speech timing is a core feature of the praxis disorder that defines a developmental form of apraxia of speech.

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

A companion paper addresses the need for phenotype markers for speech-genetics studies and provides reference data for US English rhotics that can be used for phenotype research. The present paper uses these reference data to derive and test an acoustic marker to discriminate the residual /з/ distortions of adolescents with two speech disorder histories. One speech disorder history includes significant speech delay; the other history is a speech disorder limited to only speech sound distortions of /r/, /з/ and/or /e/. The first subtype of speech delay is posited to be genetically transmitted, whereas the origins of the second subtype are posited to be associated with shared and non-shared environmental variance. Speech samples from 84 9 to 17-year-old speakers were divided into four groups based on speech history and speech errors at assessment. Group 1 children had prior speech delay and residual rhotic distortions, Group 2 children had only prior and residual rhotic distortions, and children in the two control groups had normal or normalized speech. Statistically significant logistic regression models indicated that an acoustic marker successfully discriminated residual derhotacized /з/ tokens produced by speakers in Group 1 from residual derhotacized /з/ tokens produced by speakers in Group 2. The marker was a z score less than 6.0 for Formant 2 subtracted from Formant 3 (i.e. zF3-F2<6.0) as measured at the constriction interval for /з/ targets. Sensitivity (percentage of correctly identified derhotacized /з / tokens from Group 1 speakers) for the acoustic marker was 85%. Specificity (percentage of correctly rejected derhotacized /϶/ tokens from Group 2 speakers) was 79%. Discussion considers methodological, phonological, and genetic perspectives that might account for the articulatory differences in the residual /з/ distortions of adolescents with the two different speech histories.

A diagnostic marker for speech delay associated with otitis media with effusion: backing of obstruents

A companion paper in this issue reported diagnostic accuracy findings for a marker (the Intelligibility‐Speech Gap) to identify speech delay associated with otitis media with effusion (SD‐OME). The present paper reports findings for another possible diagnostic marker for SD‐OME—Backing of Obstruents. Conversational speech samples and citation forms from 48 speech‐delayed children with positive and negative histories for OME were analysed using both perceptual and acoustic methods. The perceptual findings indicated significant trends for backing to be more prevalent in children with positive compared to negative histories of OME. Among a number of candidate speech error variables, lowered first spectral moments on lingual stops and sibilant fricatives as obtained from moments analysis emerged as a promising acoustic correlate of backing. Positive and negative predictive values, and sensitivity and specificity values for the acoustic marker, were above 75% for each of three stimulus words targeting /k/, /z/ and /∫/. Discussion considers alternative explanatory perspectives on the ontogenetic development of backing in children who have experienced the fluctuant hearing loss associated with early recurrent OME.

Acoustic phenotypes for speech-genetics studies: reference data for residual /з/ distortions

An eventual genetic account of at least one subtype of child speech disorders may require the use of acoustic markers to phenotype children and family members. Acoustic markers have the potential for sensitivity and specificity that are not available using auditory-perceptual procedures such as phonetic transcription. Prior reports on the use of acoustics in speech-genetics research have described methods to complete large-scale acoustic analyses, addressed relevant technical and linguistic sampling issues, and provided an acoustic reference database for /s/ production in adolescents. The present paper addresses additional methodological issues and demonstrates how reference data might be used for speech-genetics studies of another class of frequently persisting speech errors - distortions of the English rhotics /r/ and /з/. Findings support the need to adjust acoustic reference data by age and gender, and to subgroup reference data by rhotic phoneme and phonetic context. We describe a z score procedure t...An eventual genetic account of at least one subtype of child speech disorders may require the use of acoustic markers to phenotype children and family members. Acoustic markers have the potential for sensitivity and specificity that are not available using auditory-perceptual procedures such as phonetic transcription. Prior reports on the use of acoustics in speech-genetics research have described methods to complete large-scale acoustic analyses, addressed relevant technical and linguistic sampling issues, and provided an acoustic reference database for /s/ production in adolescents. The present paper addresses additional methodological issues and demonstrates how reference data might be used for speech-genetics studies of another class of frequently persisting speech errors - distortions of the English rhotics /r/ and /з/. Findings support the need to adjust acoustic reference data by age and gender, and to subgroup reference data by rhotic phoneme and phonetic context. We describe a z score procedure that accommodates these methodological needs. A companion paper uses these data to develop an acoustic phenotype marker of residual /з/ distortions for speech-genetics research.

Perceptual and acoustic reliability estimates for the Speech Disorders Classification System (SDCS)

A companion paper describes three extensions to a classification system for paediatric speech sound disorders termed the Speech Disorders Classification System (SDCS). The SDCS uses perceptual and acoustic data reduction methods to obtain information on a speakers speech, prosody, and voice. The present paper provides reliability estimates for the two perceptual methods (narrow phonetic transcription; prosody-voice coding) and the acoustic analysis methods the SDCS uses to describe and classify a speakers speech competence, precision, and stability. Speech samples from 10 speakers, five with significant motor speech disorder and five with typical speech, were re-measured to estimate intra-judge and inter-judge agreement for the perceptual and acoustic methods. Each of the speakers completed five speech tasks (total = 50 datasets), ranging in articulatory difficulty for the speakers, with consequences for the difficulty level of data reduction. Point-to-point percentage of agreement findings for the two perceptual methods were as high or higher than reported in literature reviews and from previous studies conducted within the laboratory. Percentage of agreement findings for the acoustics tasks of segmenting phonemes, editing fundamental frequency tracks, and estimating formants ranged from values in the mid 70% to 100%, with most estimates in the mid 80% to mid 90% range. Findings are interpreted as support for the perceptual and acoustic methods used in the SDCS to describe and classify speakers with speech sound disorders.

Clinical research with the prosody-voice screening profile

The Prosody-Voice Screening Profile (PVSP) is a clinical research instrument that quantifies a speakers conversational speech status in seven suprasegmental domains: phrasing, rate, stress, loudness, pitch, laryngeal quality and resonance. The PVSP has been used to assess the prosody-voice characteristics of children and adult speakers with typical speech-language development and with a variety of speech-language disorders of known and unknown origin. PVSP coding requires a trained examiner to determine, on an utterance-by-utterance basis within each of the seven domains, whether a speakers prosody-voice characteristics can be defined as appropriate based on a set of auditory-perceptual criteria. This report provides brief overviews of the development, administration, and psychometric features of this screening tool, and summarizes prosody-voice findings to date for several typically speaking and clinical populations.The Prosody-Voice Screening Profile (PVSP) is a clinical research instrument that quantifies a speakers conversational speech status in seven suprasegmental domains: phrasing, rate, stress, loudness, pitch, laryngeal quality and resonance. The PVSP has been used to assess the prosody-voice characteristics of children and adult speakers with typical speech-language development and with a variety of speech-language disorders of known and unknown origin. PVSP coding requires a trained examiner to determine, on an utterance-by-utterance basis within each of the seven domains, whether a speakers prosody-voice characteristics can be defined as appropriate based on a set of auditory-perceptual criteria. This report provides brief overviews of the development, administration, and psychometric features of this screening tool, and summarizes prosody-voice findings to date for several typically speaking and clinical populations.

A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: II. Validity Studies of the Pause Marker

Purpose The purpose of this 2nd article in this supplement is to report validity support findings for the Pause Marker (PM), a proposed single-sign diagnostic marker of childhood apraxia of speech (CAS). Method PM scores and additional perceptual and acoustic measures were obtained from 296 participants in cohorts with idiopathic and neurogenetic CAS, adult-onset apraxia of speech and primary progressive apraxia of speech, and idiopathic speech delay. Results Adjusted for questionable specificity disagreements with a pediatric Mayo Clinic diagnostic standard, the estimated sensitivity and specificity, respectively, of the PM were 86.8% and 100% for the CAS cohort, yielding positive and negative likelihood ratios of 56.45 (95% confidence interval [CI]: [1.15, 2763.31]) and 0.13 (95% CI [0.06, 0.30]). Specificity of the PM for 4 cohorts totaling 205 participants with speech delay was 98.5%. Conclusion These findings are interpreted as providing support for the PM as a near-conclusive diagnostic marker of CAS.

A diagnostic marker to discriminate childhood apraxia of speech from speech delay: I. development and description of the pause marker

Purpose The goal of this article (PM I) is to describe the rationale for and development of the Pause Marker (PM), a single-sign diagnostic marker proposed to discriminate early or persistent childhood apraxia of speech from speech delay. Method The authors describe and prioritize 7 criteria with which to evaluate the research and clinical utility of a diagnostic marker for childhood apraxia of speech, including evaluation of the present proposal. An overview is given of the Speech Disorders Classification System, including extensions completed in the same approximately 3-year period in which the PM was developed. Results The finalized Speech Disorders Classification System includes a nosology and cross-classification procedures for childhood and persistent speech disorders and motor speech disorders (Shriberg, Strand, & Mabie, 2017). A PM is developed that provides procedural and scoring information, and citations to papers and technical reports that include audio exemplars of the PM and reference data used to standardize PM scores are provided. Conclusions The PM described here is an acoustic-aided perceptual sign that quantifies one aspect of speech precision in the linguistic domain of phrasing. This diagnostic marker can be used to discriminate early or persistent childhood apraxia of speech from speech delay.

A Diagnostic Marker to Discriminate Childhood Apraxia of Speech From Speech Delay: IV. The Pause Marker Index

Purpose Three previous articles provided rationale, methods, and several forms of validity support for a diagnostic marker of childhood apraxia of speech (CAS), termed the pause marker (PM). Goals of the present article were to assess the validity and stability of the PM Index (PMI) to scale CAS severity. Method PM scores and speech, prosody, and voice precision-stability data were obtained for participants with CAS in idiopathic, neurogenetic, and complex neurodevelopmental disorders; adult-onset apraxia of speech consequent to stroke and primary progressive apraxia; and idiopathic speech delay. Three studies were completed including criterion and concurrent validity studies of the PMI and a temporal stability study of the PMI using retrospective case studies. Results PM scores were significantly correlated with other signs of CAS precision and stability. The best fit of the distribution of PM scores to index CAS severity was obtained by dividing scores into 4 ordinal severity classifications: mild, mild-moderate, moderate-severe, and severe. Severity findings for the 4 classifications and retrospective longitudinal findings from 8 participants with CAS supported the validity and stability of the PMI. Conclusion Findings support research and clinical use of the PMI to scale the severity of CAS.