Assessment of adult speech disorders: current situation and needs in French-speaking clinical practice

Automatic modelling of perceptual judges in the context of head and neck cancer speech intelligibility

BACKGROUND

Perceptual measures such as speech intelligibility are known to be biased, variant and subjective, to which an automatic approach has been seen as a more reliable alternative. On the other hand, automatic approaches tend to lack explainability, an aspect that can prevent the widespread usage of these technologies clinically.

AIMS

In the present work, we aim to study the relationship between four perceptual parameters and speech intelligibility by automatically modelling the behaviour of six perceptual judges, in the context of head and neck cancer. From this evaluation we want to assess the different levels of relevance of each parameter as well as the different judge profiles that arise, both perceptually and automatically.

METHODS AND PROCEDURES

Based on a passage reading task from the Carcinologic Speech Severity Index (C2SI) corpus, six expert listeners assessed the voice quality, resonance, prosody and phonemic distortions, as well as the speech intelligibility of patients treated for oral or oropharyngeal cancer. A statistical analysis and an ensemble of automatic systems, one per judge, were devised, where speech intelligibility is predicted as a function of the four aforementioned perceptual parameters of voice quality, resonance, prosody and phonemic distortions.

OUTCOMES AND RESULTS

The results suggest that we can automatically predict speech intelligibility as a function of the four aforementioned perceptual parameters, achieving a high correlation of 0.775 (Spearman's ρ). Furthermore, different judge profiles were found perceptually that were successfully modelled automatically.

CONCLUSIONS AND IMPLICATIONS

The four investigated perceptual parameters influence the global rating of speech intelligibility, showing that different judge profiles emerge. The proposed automatic approach displayed a more uniform profile across all judges, displaying a more reliable, unbiased and objective prediction. The system also adds an extra layer of interpretability, since speech intelligibility is regressed as a direct function of the individual prediction of the four perceptual parameters, an improvement over more black box approaches.

WHAT THIS PAPER ADDS

What is already known on this subject Speech intelligibility is a clinical measure typically used in the post-treatment assessment of speech affecting disorders, such as head and neck cancer. Their perceptual assessment is currently the main method of evaluation; however, it is known to be quite subjective since intelligibility can be seen as a combination of other perceptual parameters (voice quality, resonance, etc.). Given this, automatic approaches have been seen as a more viable alternative to the traditionally used perceptual assessments. What this study adds to existing knowledge The present work introduces a study based on the relationship between four perceptual parameters (voice quality, resonance, prosody and phonemic distortions) and speech intelligibility, by automatically modelling the behaviour of six perceptual judges. The results suggest that different judge profiles arise, both in the perceptual case as well as in the automatic models. These different profiles found showcase the different schools of thought that perceptual judges have, in comparison to the automatic judges, that display more uniform levels of relevance across all the four perceptual parameters. This aspect shows that an automatic approach promotes unbiased, reliable and more objective predictions. What are the clinical implications of this work? The automatic prediction of speech intelligibility, using a combination of four perceptual parameters, show that these approaches can achieve high correlations with the reference scores while maintaining a certain degree of explainability. The more uniform judge profiles found on the automatic case also display less biased results towards the four perceptual parameters. This aspect facilitates the clinical implementation of this class of systems, as opposed to the more subjective and harder to reproduce perceptual assessments.

Status of prosody in the practices of speech-language pathologists in France: A survey on theoretical and clinical dimensions

PURPOSE

Many populations in the scope of speech and language pathologists (SLPs) are at risk of prosodic disorders that can impact communicative ability. While a few studies have examined the importance of prosody in the clinical practice of English-speaking SLPs, there is a lack of similar research in non-English-speaking countries. The current study aimed to establish an overview of the situation in France and to determine factors that might be associated with assessing and treating prosody.

METHOD

We collected data about the theoretical and clinical dimensions related to prosody from SLPs in France using an online survey.

RESULTS

One hundred and twenty-eight valid responses were analyzed. Results suggest that both emotional and linguistic prosodies are examined by SLPs. Some aspects of prosody seem to be mastered better than others. While they are aware of the major prosodic difficulties in various pathologies and their negative impact, most SLPs in France rarely or never assess prosody. They feel more uncomfortable with it than with other speech-language domains and often do not consider it as a therapeutic target. Importantly, the perception of prosody as a therapeutic tool is associated with the frequency of assessing and addressing prosodic impairment.

CONCLUSIONS

Further studies should focus on identifying the factors that could improve practices and developing comprehensive assessment tools and evidence-based intervention methods in French. Providing better training in prosody and setting up more collaborations between SLPs and researchers in linguistics and psycholinguistics would be keys in developing this field.

Criteria for creating new standard reading passages for the assessment of speech and voice: A Delphi consensus study

Standard reading passages allow for the study of the integrated functions of speech and voice components in contextual, running speech, with target stimuli in a controlled environment. In both clinical practice and research, these texts provide rapid insight into the characteristics of the patient's speech, with fewer hesitations than in conversational speech and better predictability by the evaluator. Although a plethora of texts exist in different languages, they present various limitations. A specifically created standardised text in each language allowing for an ecological assessment of speech and voice functions, meeting most required criteria for standard speech and voice assessment and adapted to the target language's cultural and linguistic specificities, would therefore be an interesting option. However, no guidelines exist for the creation of such a reading passage. This article describes the international Delphi consensus study carried out to identify a minimal set of criteria to take into account when creating standard reading passages for an overall speech and voice assessment in adolescents and adults. This survey was conducted in three consecutive rounds; forty experts participated in the first round, with a total dropout of 17% from round 1 to round 3. It results in a minimal set of ten criteria which were selected by a majority of the experts and were rated as most important. This set contains five phoneme-level, two word-level, two sentence-level criteria and one global-level criterion. It can be used as a general guideline for the creation of standard reading passages in Indo-European Romance and Germanic languages such as English, French and German. The construction of a new reading passage in French following this guideline is briefly described.

Intelligibility and comprehensibility: A Delphi consensus study

BACKGROUND

Intelligibility and comprehensibility in speech disorders can be assessed both perceptually and instrumentally, but a lack of consensus exists regarding the terminology and related speech measures in both the clinical and scientific fields.

AIMS

To draw up a more consensual definition of intelligibility and comprehensibility and to define which assessment methods relate to both concepts, as part of their definition.

METHODS & PROCEDURES

A three-round modified Delphi consensus study was carried out among clinicians, researchers and lecturers engaged in activities in speech disorders.

OUTCOMES & RESULTS

Forty international experts from different fields (mainly clinicians, linguists and computer scientists) participated in the elaboration of a comprehensive definition of intelligibility and comprehensibility and their assessment. While both concepts are linked and contribute to functional human communication, they relate to two different reconstruction levels of the transmitted speech material. Intelligibility refers to the acoustic-phonetic decoding of the utterance, while comprehensibility relates to the reconstruction of the meaning of the message. Consequently, the perceptual assessment of intelligibility requires the use of unpredictable speech material (pseudo-words, minimal word pairs, unpredictable sentences), whereas comprehensibility assessment is meaning and context related and entails more functional speech stimuli and tasks.

CONCLUSION & IMPLICATIONS

This consensus study provides the scientific and clinical communities with a better understanding of intelligibility and comprehensibility. A comprehensive definition was drafted, including specifications regarding the tasks that best fit their assessment. The outcome has implications for both clinical practice and scientific research, as the disambiguation improves communication between professionals and thereby increases the efficiency of patient assessment and care and benefits the progress of research as well as research translation.

WHAT THIS PAPER ADDS

What is already known on the subject Intelligibility and comprehensibility in speech disorders can be assessed both perceptually and instrumentally, but a lack of consensus exists regarding the terminology and related speech measures in both the clinical and scientific fields. What this paper adds to existing knowledge This consensus study allowed for a more consensual and comprehensive definition of intelligibility and comprehensibility and their assessment, for clinicians and researchers. The terminological disambiguation helps to improve communication between experts in the field of speech disorders and thereby benefits the progress of research as well as research translation. What are the potential or actual clinical implications of this work? Unambiguous communication between professionals, for example, in a multidisciplinary team, allows for the improvement in the efficiency of patient care. Furthermore, this study allowed the assessment tasks that best fit the definition of both intelligibility and comprehensibility to be specified, thereby providing valuable information to improve speech disorder assessment and its standardization.