The Nature of Nasal Fricatives: Articulatory-Perceptual Characteristics and Etiologic Considerations

The impact of enhanced Milieu teaching with phonological emphasis (EMT + PE) on the speech and language outcomes for toddlers with cleft palate in Brazil and the United States of America

PURPOSE

The purpose of this study was to compare the speech and language outcomes of children with cleft palate with or without cleft lip (CP+/-L) in the USA to children with CP+/-L in Brazil who underwent intervention with enhanced Milieu teaching with phonological emphasis (EMT + PE), as there are few cross-country intervention comparisons for children with CP+/-L.

METHOD

This is a retrospective analysis of 29 participants from the USA and 24 participants from Brazil who were matched on age. The US participants were between the ages of 13-35 months (M = 23.76), spoke Standard American English in the home, and were recruited from East Tennessee State University and Vanderbilt University. The Brazilian participants were between the ages of 20-34 months (M = 25.04), spoke Brazilian Portuguese in the home, and were recruited from the Hospital de Reabilitação de Anomalias Craniofaciais-Universidade de São Paulo. All treatment participants received EMT + PE from trained speech-language pathologists in hospital-university clinics.

RESULT

The treatment groups demonstrated greater gains than comparison groups in percent consonants correct, number of different words, and expressive/receptive vocabulary. There was no main effect nor interaction by country.

CONCLUSION

The application of EMT + PE in a second culture and language is a viable early intervention option for participants with CP+/-L.

Considering the role of speech processing in cleft-related speech sound disorders: Implications for causal pathways and classification systems

BACKGROUND

Classification systems in healthcare support shared understanding of conditions for clinical communication, service monitoring and development, and research. Children born with cleft palate with or without cleft lip (CP+/-L) are at high risk of developing cleft-related speech sound disorder (SSD). The way cleft-related SSD is represented and described in SSD classification systems varies. Reflecting on the potential causal pathways for different cleft-related speech features, including the role of speech processing skills, may inform how cleft-related SSD is represented in classification systems.

AIM & APPROACH

To explore and reflect on how cleft-related SSD is represented in current SSD classification systems in the context of considering how speech processing skills and other factors may be involved in causal pathways of cleft speech characteristics (CSCs).

MAIN CONTRIBUTION

Variation in the representation of cleft-related SSD in classification systems is described. Potential causal pathways for passive cleft- related speech features and different active CSCs are explored. The factors involved in the development and/or persistence of different active CSCs may vary. Some factors may be specific to children born with CP+/-L, but if speech processing skills are also involved, this is an overlap with other SSD subtypes. Current evidence regarding relationships between different speech processing skills and active CSCs is limited. Implications for the representation of cleft-related SSD in SSD classification systems are discussed.

CONCLUSION

There are different categories of cleft-related speech features which are essential to understand and identify in children with cleft-related SSD to ensure appropriate management. Representation of these feature categories in classification systems could support understanding of speech in this population. Speech processing skills could be involved in the development and/or persistence of different active CSCs in individual children. Reflection and discussion on how cleft-related SSD is represented in classification systems in relation to other SSD subtypes may inform future iterations of these systems. Further work is needed to understand factors influencing the development and/or persistence of active CSCs, including speech processing skills.

WHAT THIS PAPER ADDS

What is already known on the subject Cleft-related speech sound disorder (SSD) is commonly described as being of known origin. The features of cleft-related SSD have been described extensively and several authors have also examined factors which may contribute to speech development and outcomes in children born with cleft palate +/- lip. There is limited evidence regarding the role of speech processing in the development and persistence of cleft-related SSD. What this study adds This paper reflects on how cleft-related SSD is represented in SSD classification systems in relation to key feature categories of cleft-related SSD and possible causal pathways for passive features and active cleft speech characteristics (CSCs). The role of cognitive speech processing skills is specifically considered alongside other factors that may contribute to the development of active CSCs. What are the clinical implications of this work? Causal pathways for different features of cleft-related SSD may vary, particularly between passive and active features, abut also between different active CSCs. Speech and language therapists (SLTs) need to differentially diagnose passive speech features and active CSCs. Consideration of the role of different speech processing skills and interactions with other potentially influencing factors in relation to active CSCs may inform clinical hypotheses and speech and language therapy (SLT) intervention. Representing key features of cleft-related SSD in classification systems may support understanding of cleft-related SSD in relation to other SSD subtypes.

How differences in anatomy and physiology and other aetiology affect the way we label and describe speech in individuals with cleft lip and palate

BACKGROUND

Speech in individuals with cleft lip and/or palate (CLP) is a complex myriad of presenting symptoms. It is uniquely associated with the structural difference of velopharyngeal insufficiency (VPI), together with a wide and heterogeneous range of other aetiologies which often co-occur. The nature of the speech sound disorder (SSD) including VPI may also change over the course of an individual's care pathway. Differences in terminology and approaches to analysis are currently used, resulting in confusion internationally. Additionally, current diagnostic labels and classification systems in SSD do not capture the complexity and full nature of speech characteristics in CLP.

AIMS

This paper aims to explore the different aetiologies of cleft palate/VPI speech and to relate aetiology with speech characteristic(s). In so doing, it attempts to unravel the different terminology used in the field, describing commonalities and differences, and identifying overlaps with the speech summary patterns used in the United Kingdom and elsewhere. The paper also aims to explore the applicability of current diagnostic labels and classification systems in the non-cleft SSD literature and illustrate certain implications for speech intervention in CLP.

METHODS AND PROCEDURES

The different aetiologies were identified from the literature and mapped onto cleft palate/VPI speech characteristics. Different terminology and approaches to analysis are defined and overlaps described. The applicability of current classification systems in SSD is discussed including additional diagnostic labels proposed in the field.

OUTCOMES AND RESULTS

Aetiologies of cleft palate/VPI speech identified include developmental (cognitive-linguistic), middle ear disease and fluctuating hearing loss, altered oral structure, abnormal facial growth, VPI-structural (abnormal palate muscle) and VPI-iatrogenic (maxillary advancement surgery). There are four main terminologies used to describe cleft palate/VPI speech: active/passive and compensatory/obligatory, which overlap with the four categories used in the UK speech summary patterns: anterior oral cleft speech characteristics (CSCs), posterior oral CSCs, non-oral CSCs and passive CSCs, although not directly comparable. Current classification systems in non-cleft SSD do not sufficiently capture the full nature and complexity of cleft palate/VPI speech.

CONCLUSIONS AND IMPLICATIONS

Our attempt at identifying the heterogeneous range of aetiologies provides clinicians with a better understanding of cleft palate/VPI speech to inform the management pathway and the nature and type of speech intervention required. We hope that the unravelling of the different terminology in relation to the UK speech summary patterns, and those used elsewhere, reduces confusion and provides more clarity for clinicians in the field. Diagnostic labels and classification require international agreement.

WHAT THIS PAPER ADDS

What is already known on the subject Speech associated with cleft palate/velopharyngeal insufficiency (VPI) is a complex myriad of speech characteristics with a wide and heterogeneous range of aetiologies. Different terminology and speech summary patterns are used to describe the speech characteristics. The traditional classification of cleft palate/VPI speech is Articulation Disorder, although evidence is building for Phonological Disorder and contrastive approaches in cleft speech intervention. What this paper adds to existing knowledge This paper explores the range of aetiologies of cleft palate/VPI speech (e.g., altered oral structure, abnormal facial growth, abnormal palate muscle and iatrogenic aetiologies) and attempts to relate aetiology with speech characteristic(s). An attempt is made at unravelling the different terminology used in relation to a well-known and validated approach to analysis, used in the United Kingdom and elsewhere. Complexities of current diagnostic labels and classifications in Speech Sound Disorder to describe cleft palate/VPI speech are discussed. What are the potential or actual clinical implications of this work? There needs to be a common language for describing and summarising cleft palate/VPI speech. Speech summary patterns based on narrow phonetic transcription and correct identification of aetiology are essential for the accurate classification of the speech disorder and identification of speech intervention approaches. There is an urgent need for research to identify the most appropriate type of contrastive (phonological) approach in cleft lip and/or palate.

Treatment of Speech Sound Errors in Cleft Palate: A Tutorial for Speech-Language Pathology Assistants

PURPOSE

Cleft palate is one of the most common birth defects in the United States. Most of these children receive speech therapy by preschool and school-based clinicians. The purpose of this article is to provide a comprehensive tutorial for speech-language pathology assistants (SLPAs) regarding treatment techniques and principles for children with cleft palate.

METHOD

It has been reported that 68% of preschoolers with repaired cleft palate received speech therapy. Preschool and school-based speech-language pathologists (SLPs) have reported a strong desire for practical professional development and continuing education resources regarding treatment of children with cleft palate. Thus, it seems likely that SLPAs may feel similarly unequipped to provide effective treatment for children with cleft palate. Obligatory and learned speech errors commonly found in children with cleft palate are described. Elicitation strategies for compensatory articulations are detailed. The implementation of evidence-based articulation and phonological treatment approaches is described in a step-by-step manner. "Red flags" that may arise during treatment and require input from the supervising SLP are highlighted.

RESULTS

SLPAs will learn elicitation techniques for compensatory articulations and implement evidence-based treatment approaches to improve the speech accuracy of children with cleft palate.

CONCLUSION

It is important for all school-based clinicians to be familiar with speech therapy for individuals with cleft palate.

Compensatory Articulation Errors in Patients With Velopharyngeal Dysfunction and Palatal Anomalies

PURPOSE

The aim of this study was to assess the frequency and types of compensatory articulations (CAs) in nonsyndromic patients with velopharyngeal dysfunction (VPD) and various palatal anomalies and to determine the relationship between the frequency of CAs, type of palatal anomaly, and phonological errors.

METHOD

A total of 783 nonsyndromic, Hebrew-speaking patients with VPD and various palatal anomalies (cleft lip and palate [CLP], cleft palate [CP], submucous CP [SMCP], occult submucous CP [OSMCP], or non-CP) were studied retrospectively. Perceptual VPD tests, including articulation and phonological assessment, were conducted. CAs were described as below the level of the defect in the vocal tract (abnormal backing of oral targets to post-uvular place) or in front of it within the oral cavity (palatalization) and at the velopharyngeal port.

RESULTS

Among 783 patients, 213 (27.2%) had CAs. Most CAs (18.4%) occurred below the level of the defect, followed by CAs at the velopharyngeal port (12.0%) or in front of it (4.9%). No differences were found in the frequency of CAs between patients with CP (47.8%) or CLP (52.6%) and between those with non-CP (13.6%) or OSMCP (14.7%). SMCP patients had lower frequency of CAs (29.8%) than CP (p = .003) and CLP (p =  .002) patients but higher frequency than OSMCP (p = .002) and non-CP (p =  .002) patients did. Among the 783 patients, 247 (31.5%) had phonological errors. A higher frequency of phonological errors was found in patients with CAs (55.4%) compared to those without (22.6%) and in all palatal anomaly groups except CLP (31.4% vs. 23.9%).

CONCLUSIONS

CAs in nonsyndromic patients with VPD remained relatively high in all age groups, up to adulthood. CAs are influenced by inadequate velar length following palatal repair, as well as by oral structural abnormalities, whereas poor muscle function due to OSMCP and/or abnormal size and/or shape of nasopharynx has less influence. Errors produced in front of the velopharyngeal port are influenced by the structural anomaly of CLP. This information may contribute to general phonetic and phonological theories and genetic investigations about CP anomalies.

Treatment of active nasal fricatives substituting /s/ in young children with normal palatal function using motor-based intervention

Purpose: The aim was to evaluate the effect of a motor-based, hierarchically structured intervention directed at active nasal fricatives substituting /s/ in young children with normal palatal function.Method: An experimental single-subject design was replicated across three children, aged 4-6 years, with normal palatal function, who substituted oral /s/ with active nasal fricatives. Treatment was performed weekly by a speech-language pathologist and included home training conducted by parents. Audio documented probes were registered regularly and /s/-production evaluated as oral or nasal.Result: All children achieved 98-100% oral production of /s/ in six probed linguistic contexts at treatment end and exhibited good maintenance at follow-up. The four-year-olds showed gradual or inconsistent response and slower progress, the six-year-old direct response and faster progress.Conclusion: The study provides preliminary evidence suggesting positive intervention effects for treating active nasal fricatives in children with normal palatal function. However, possible confounding effects such as maturation or repeated testing could not be ruled out; thus, results need to be replicated with increased experimental control. Nevertheless, the study adds to the currently meagre empirical evidence-base for the population. Individual treatment response and progress patterns were found and data suggests that the intervention may be beneficial from age 4.

Development and Resolution of Nasal Fricatives in a Child with Repaired Bilateral Cleft Lip and Palate: A Case Report

PURPOSE

This case report describes the development, characteristics, and resolution of anterior nasal fricatives (ANFs) - a learned maladaptive articulation error - in a young girl with repaired bilateral cleft lip and palate.

METHOD

The girl was observed every two months from 12 to 24 months of age with follow-ups at 36, 48, and 67 months of age.

RESULTS

At 12 months of age, the girl nasalized /b/ inconsistently and had mild conductive hearing loss. At 18 months of age, she exhibited audible nasal air emission on some plosives and used ANFs to replace /s/ and /z/, often with a nasal grimace. At 24 months of age, the child continued to experience mild conductive hearing loss, obligatory nasal air emission, and ANFs for /s/ and /z/. At 36 months of age, pressure-flow testing documented significant velopharyngeal (VP) dysfunction. The girl then used ANFs for /f/ and /s/, phonetically marked by different oral stops. At 48 months of age, although VP impairment continued, speech therapy largely eliminated ANFs. By 67 months of age, VP closure was nearly normal.

CONCLUSIONS

Multiple factors including VP dysfunction, audible nasal air emission, and conductive hearing loss contributed to the development of ANFs. Clinical and etiological implications are discussed.

Non-Oral Compensatory Misarticulations Revisited

Non-oral compensatory misarticulation patterns are often associated with the speech of children with cleft palate. Despite their saliency, the etiology, frequency, and treatment of these misarticulations have not been studied extensively. The purpose of this commentary is to review what we know about these atypical patterns of articulation and address clinical assumptions regarding their etiology and treatment.

Reliability of Outcome Measures to Assess Consonant Proficiency Following Cleft Palate Speech Intervention: The Percentage of Consonants Correct Metric and the Probe Scoring System

Purpose This study compared the inter- and intrarater reliability of the percentage of consonants correct (PCC) metrics and the probe scoring system between an experienced and a less experienced rater and between two experienced raters. In addition, these outcome measures' ability to reflect changes following speech intervention was measured. Method During Phase 1, two raters (Rater 1 with 5 years of experience in cleft-related speech disorders and Rater 2 with limited experience in cleft-related speech disorders) independently assessed 134 speech samples at the word and sentence levels, which were collected on different data points before, during, and following a cleft palate speech intervention. During Phase 2, a third rater (with 8 years of experience) analyzed 34 speech samples. The percentage of consonants correct-revised, the percentage of correct places and manners, and probe scores at the word and sentence levels were measured. Results Poor-to-moderate interreliability between Raters 1 and 2 was found due to differences in error classification. Interrater reliability between Raters 1 and 3 was very good for both the PCC metrics and the probe scores. The interrater reliability for the amount of targets elicited was lower compared to the interrater reliability for the amount of targets correct. The probe scoring system demonstrated a greater ability to detect changes toward the correct production of the target consonant compared to the PCC metrics. Conclusions Having an experience with the assessment of cleft-related speech disorders is a crucial factor to gain reliable results. The interrater reliability for the PCC metrics and the probe scoring system between two experienced raters did not differ, suggesting that both outcome measures can be used in cleft palate speech intervention studies. Despite the ability of the probe scoring system to detect changes, further research should provide insight in the benefits of this system both for research and clinical purposes.

Obligatory Nasal Turbulence as a Trigger for the Development of Posterior Nasal Fricatives in a Child With Repaired Cleft Palate

Posterior nasal fricatives (PNFs) are unusual articulations that occur in some children with and without cleft palate. The etiology of PNFs is unclear. A young girl with repaired cleft palate is described who exhibited inconsistent obligatory nasal turbulence during production of stops at 2 years of age. At 3 years of age, she exhibited various phonological processes and used PNFs to replace sibilants and affricates. Pressure-flow testing showed a relatively small velopharyngeal area during production of stops. These observations are consistent with obligatory nasal turbulence triggering the development of PNFs as an unusual phonological process, perhaps facilitated by reduced hearing.

Effect of motor-based speech intervention on articulatory placement in the treatment of a posterior nasal fricative: a preliminary MRI study on a single subject

BACKGROUND

Posterior nasal fricatives are a learned compensatory articulation error and commonly substituted for oral fricatives. Treatment of such articulation errors requires the modification or teaching of skilled movements. A motor-based approach is designed to teach the complex motor skill movement sequences required in the production of sounds. Although motor learning research is well established, little has been done to determine how the approach changes the underlying physiology of articulatory movements. While the underlying anatomical configuration of the posterior nasal fricative has been described, no studies have quantified anatomic and physiological changes pre- and post-treatment.

AIMS

To use magnetic resonance imaging (MRI) to visualize and quantify the results of motor-based speech-intervention approach on articulatory placement for the treatment of the posterior nasal fricative.

METHODS & PROCEDURES

A 6-year-old male with a history of ear infections and posterior nasal fricative substitution for /s/ underwent six 1-h sessions of a motor-based treatment approach over the course of 2 weeks. Pre- and post-treatment evaluation included perceptual and instrumental assessment of speech and resonance. Perceptual resonance was rated by two speech-language therapists and articulation was assessed at the single-word level. Instrumental assessment included the See-Scape, Nasometer II and MRI during the sustained phonation of /s/. Amira v5.6 Visualization and Volume modelling software used the midsagittal and oblique coronal plane to measure dimensions of the articulatory anatomy.

OUTCOMES & RESULTS

Interrater reliability was assessed using a Pearson product moment correlation (α = .05) and ranged from r = .91 to .95. Intra-rater reliability was assessed using the intra-class correlation coefficient (.976) demonstrating a high degree of reliability with a 95% confidence interval. Articulation improved from 0% accuracy for /s/ in isolation at baseline to 100% for /s/ at the word level and 95% accuracy during conversational speech by session 6. Post-treatment results from this study revealed a greater shortening of the levator veli palatini (levator) muscle length during articulatory movements, more pronounced velar knee and dimple, decreased velar thickness, increased velar length and altered tongue position.

CONCLUSIONS & IMPLICATIONS

This study demonstrated the use of pre- and post-treatment imaging methodology to quantify articulatory changes following an intensive motor-based treatment approach. MRI demonstrated quantifiable changes in articulatory placement. Individuals who exhibit non-developmental and phoneme-specific articulation errors, such as the posterior nasal fricative, may be excellent candidates for short-term, intensive and frequent speech therapy sessions to remediate the production of the posterior nasal fricative.