Importance of glottis landmarks for the assessment of cleft lip and palate speech intelligibility.

The present work explores the acoustic characteristics of articulatory deviations near g(lottis) landmarks to derive the correlates of cleft lip and palate speech intelligibility. The speech region around the g landmark is used to compute two different acoustic features, namely, two-dimensional discrete cosine transform based joint spectro-temporal features, and Mel-frequency cepstral coefficients. Sentence-specific acoustic models are built using these features extracted from the normal speakers' group. The mean log-likelihood score for each test utterance is computed and tested as the acoustic correlates of intelligibility. Derived intelligibility measure shows significant correlation (ρ = 0.78, p < 0.001) with the perceptual ratings.

Segmentation of binaural room impulse responses for speech intelligibility prediction.

The two most important aspects in binaural speech perception-better-ear-listening and spatial-release-from-masking-can be predicted well with current binaural modeling frameworks operating on head-related impulse responses, i.e., anechoic binaural signals. To incorporate effects of reverberation, a model extension was proposed, splitting binaural room impulse responses into an early, useful, and late, detrimental part, before being fed into the modeling framework. More recently, an interaction between the applied splitting time, room properties, and the resulting prediction accuracy was observed. This interaction was investigated here by measuring speech reception thresholds (SRTs) in quiet with 18 normal-hearing subjects for four simulated rooms with different reverberation times and a constant room geometry. The mean error with one of the most promising binaural prediction models could be reduced by about 1 dB by adapting the applied splitting time to room acoustic parameters. This improvement in prediction accuracy can make up a difference of 17% in absolute intelligibility within the applied SRT measurement paradigm.

Minimally Detectable Change and Minimal Clinically Important Difference of a Decline in Sentence Intelligibility and Speaking Rate for Individuals With Amyotrophic Lateral Sclerosis.

Purpose: The purpose of this study was to determine the minimally detectable change (MDC) and minimal clinically important difference (MCID) of a decline in speech sentence intelligibility and speaking rate for individuals with amyotrophic lateral sclerosis (ALS). We also examined how the MDC and MCID vary across severities of dysarthria. Method: One-hundred forty-seven patients with ALS and 49 healthy control subjects were selected from a larger, longitudinal study of bulbar decline in ALS, resulting in a total of 650 observations. Intelligibility and speaking rate in words per minute (WPM) were calculated using the Sentence Intelligibility Test (Yorkston, Beukelman, & Hakel, 2007), and the ALS Functional Rating Scale-Revised (Cedarbaum et al., 1999) was administered to capture patient perception of motor impairment. The MDC at the 95% confidence level was estimated using the following formula: MDC95 = 1.96 × âˆš2 × SEM. For estimation of the MCID, receiver operating characteristic curves were generated, and area under the curve and optimal thresholds to maximize sensitivity and specificity were calculated. Results: The MDC for sentence intelligibility was 12.07%, and the MCID was 1.43%. The MDC for speaking rate was 36.57 WPM, and the MCID was 8.80 WPM. Both MDC and MCID estimates varied with severity of dysarthria. Conclusions: The findings suggest that declines greater than 12% sentence intelligibility and 37 WPM are required to be outside measurement error and that these estimates vary widely across dysarthria severities. The MDC and MCID metrics used in this study to detect real and clinically relevant change should be estimated for other measures of speech outcomes in intervention research.

A classification based approach to speech segregation.

A key problem in computational auditory scene analysis (CASA) is monaural speech segregation, which has proven to be very challenging. For monaural mixtures, one can only utilize the intrinsic properties of speech or interference to segregate target speech from background noise. Ideal binary mask (IBM) has been proposed as a main goal of sound segregation in CASA and has led to substantial improvements of human speech intelligibility in noise. This study proposes a classification approach to estimate the IBM and employs support vector machines to classify time-frequency units as either target- or interference-dominant. A re-thresholding method is incorporated to improve classification results and maximize hit minus false alarm rates. An auditory segmentation stage is utilized to further improve estimated masks. Systematic evaluations show that the proposed approach produces high quality estimated IBMs and outperforms a recent system in terms of classification accuracy.

Classifications of vocalic segments from articulatory kinematics: healthy controls and speakers with dysarthria.

PURPOSE: In this study, the authors classified vocalic segments produced by control speakers (C) and speakers with dysarthria due to amyotrophic lateral sclerosis (ALS) or Parkinson's disease (PD); classification was based on movement measures. The researchers asked the following questions: (a) Can vowels be classified on the basis of selected measures of articulatory motions? and (b) Can classification models that are constructed from control productions classify vowels produced by speakers with dysarthria that is related to ALS and PD? METHOD: Nineteen C, 7 PD, and 8 ALS speakers participated in this study. The severity of dysarthria varied across individuals and between the 2 disorder groups. The stimuli were 6 vowels produced in 10 words embedded into sentences read at a comfortable reading rate. Movement data were collected using the x-ray microbeam. Movement measures included distances traveled, durations, and average speeds of vowel-related movement strokes. Vowels and words were classified by linear discriminant analysis with measures of articulatory motion as input variables. RESULTS: The study showed that vocalic segments could be classified using articulatory movement characteristics with up to 80% accuracy. The classification accuracy of the movement-based models depended largely on the number of articulators involved and, to a lesser extent, on the movement measure (e.g., distance, duration, speed). Classification of PD vowels was similar to that of the C group, suggesting a simple scaling of gestures as an explanation of the movement deficit in this disease. Classification performance for ALS vowels appeared to be different from that of C and PD productions. CONCLUSION: Classification of vowels was possible on the basis of their articulatory motions. ALS vowels appeared categorically different from those of C and PD speakers.

Relationships between speech intelligibility and word articulation scores in children with hearing loss.

PURPOSE: This investigation sought to determine whether scores from a commonly used word-based articulation test are closely associated with speech intelligibility in children with hearing loss. If the scores are closely related, articulation testing results might be used to estimate intelligibility. If not, the importance of direct assessment of intelligibility is reinforced. METHOD: Forty-four children with hearing losses produced words from the Goldman Fristoe Test of Articulation-Second Edition (Goldman & Fristoe, 2000) and sets of 10 short sentences. Correlation analyses were conducted between scores for 7 word-based predictor variables and percent-intelligible scores derived from listener judgments of stimulus sentences. RESULTS: Six of 7 predictor variables were significantly correlated with percent-intelligible scores. However, regression analysis revealed that no single predictor variable or multivariable model accounted for more than 25% of the variability in intelligibility scores. CONCLUSIONS: The findings confirm the importance of assessing connected speech intelligibility directly.

Analyses of speech intelligibility in patients after glossectomy and reconstruction with fasciocutaneous/myocutaneous flaps.

This study analyzed the results of speech intelligibility tests in patients with tongue cancer who had undergone resection with the aim of making surgical recommendations for flap design and inset, to improve speech function. A total of 126 patients, enrolled from 13 Japanese institutions, were classified into 3 groups according to the resected site: lateral, anterior, and combined. The lateral group was further divided into 3 subgroups and the anterior group into 2 subgroups according to the size of resection. The speech intelligibility score was analyzed based on articulatory site and mode: 5 articulatory sites (linguodentoalveolar, linguopalatal, linguovelar, and their intermediates); and 7 articulatory modes (plosives, fricatives, affricatives, grids, nasals, vowels and semivowels). Low speech intelligibility scores were recorded at sites where flaps contribute directly to the pronunciation in the lateral and combined groups and at the anterior part of the reconstructed tongue in the anterior group. Plosives and glides displayed low values in general. A radial forearm flap had higher function in the lateral group than other flaps. The type of flap had no effect in the anterior and combined groups. Surgical techniques and flap selection to improve functional status in each type of resection are discussed.

Functionally-based screening criteria for hearing-critical jobs based on the Hearing in Noise Test.

Effective communication is a crucial requirement in many workplaces to ensure safe and effective operations. Often, critical verbal communications are carried out in noise, which can be very challenging, particularly for individuals with hearing loss. Diagnostic measures of hearing, such as the audiogram, are not adequate to make accurate predictions of speech intelligibility in real-world environments for specific workers, and thus are not generally suitable as a basis for making employment decisions. Instead, the Hearing in Noise Test (HINT) has been identified and validated for use in predicting speech intelligibility in a wide range of communication environments. The approach to validation of the HINT takes into account the expected voice level of the talker, the communication distance between the talker and the listener, and a statistical model of speech intelligibility in real-world occupational noises. For each hearing-critical task, a HINT screening threshold score is derived upon specification of the minimum level of performance required of the workers. The HINT is available in several languages, so the tools developed are applicable in a wide range of settings, including multilingual workplaces.

[Numeric quantification of intelligibility in schoolchildren with isolated and combined cleft palate]. / Numerische Quantifizierung der Verständlichkeit von Schulkindern mit isolierter und kombinierter Gaumenspalte.

OBJECTIVE: Even after adequate surgical and nonsurgical treatment, combined or isolated clefts often cause functional disorders, such as speech disorders. Speech disorders vary widely in extent and can take the form, for example, of specific features of articulation, with altered nasal emission and shifted articulation, leading to reduced speech intelligibility. So far it has not been possible to describe the relationship between cleft type and intelligibility except subjective, categorical evaluation. METHODS: Intelligibility of the speech as influenced by cleft palate in 58 children aged 9+/-2 was quantified objectively and numerically by means of automatic speech recognition technology in speech recordings for the PLAKSS test [test for psycholinguistic analysis of childhood speech impairments]. It was found that 33 children had a unilateral cleft lip and palate (CLP), 9, bilateral CLP, 10, isolated cleft palate, and 6, submucosal cleft palate. As a control group, 84 children aged 9+/-1 years and with physiological articulation were recruited from a mainstream school. Speech intelligibility is expressed as word accuracy, which means the percentage of correctly recognized words in a word sequence. RESULTS: Word accuracy levels in the control group were between 39% and 84% (mean 62%+/-10%), while the children with clefts achieved values between 0% and 73% (mean 42%+/-17%). There was no difference in intelligibility between children with isolated cleft palate and those with combined cleft type. Differences were, however, found between each group and the control group (p<0.01). CONCLUSION: Speech intelligibility of children with isolated cleft palate does not significantly differ from that of children with combined cleft type including the palate, as has been objectively quantified for the first time by objective methods. In the presence of speech disorders, the need for diagnosis and therapy is just as great in children with isolated cleft palate as in children with combined cleft types.

[The surgery voice rehabilitation after total laryngectomy with the Provox system]. / Chirurgiczna rehabilitacja glosu chorych po laryngektomii calkowitej z zastosowaniem systemu provox.

THE AIM OF STUDY: Comparison the voice quality of patients after total laryngectomy using the Provox 2 voice prosthesis and patients with esophageal speech and to discuss difficulties and complications related with its implantation. MATERIAL AND METHODS: The study group consists of 39 patients after total laryngectomy and Provox puncture. 36 patients underwent primary puncture, 3 patients - secondary puncture. 32 patients underwent radiotherapy. The time starting of speech learning was approx the 9th day after total laryngectomy and 1st-3th day after secondary implantation. The authors subjectively and objectively analyzed voice of 34 patients with fistular speech and it compared with esophageal speech of 10. The spectrograms analysis of the voice was based on Remacle's scale. The study showed juxtaposition of early and late complications of patients with voice prostheses. RESULTS: 90% of patients (35 patients) learned the fistular speech. The speech was louder and more intelligible than esophageal voice in subjective estimation. The fistular voice had higher of mean volume (61,1 dB vs. 59 dB), mean longer maximum phonation time (9,5 s vs. 2,2 s), mean higher base frequency FO (108 Hz vs. 87Hz) and smaller variability of FO based on mean Jitter ratio (3,8% vs. 6,6%), mean Shimmer ratio (23,18% vs. 23,52%) and mean HPQ ratio (127,34 vs. 141,73) than esophageal voice in objective estimation. Mean range of frequency of the speech was smaller but it was in higher frequencies. The most frequent type of spectrogram was 3th type in experimental group and 2nd type in control group. The mean lifetime of prostheses was 295 days. The most common cause of replacement of the prosthesis was leakage associated with mycosis infection (26 cases). Early complications were observed. The most frequent of them was infection around the fistula during supplementary radiotherapy (7 cases after primary puncture). The most frequent of later complications was widening of fistula and leakage around prosthesis (4 cases). CONCLUSIONS: Rehabilitation of patients after total laryngectomy is better using Provox system than learning esophageal speech (according to voice quality aspect). Using of voice prostheses in patients after total laryngectomy can combine with appearance of complications.

Determinant factors of severity rating of phonological disorder.

BACKGROUND: Phonological disorder. AIM: To analyze the severity descriptors used by graduation students of the Speech-Language Communication Sciences and Speech-Language Pathologists to classify the phonological disorder. METHOD: 60 judges classified the speech of 50 phonological disordered children regarding the severity of the disorder, after listening to their speech samples. RESULTS: The most used and applied severity descriptors, to justify the severity of the disorder, were: phonology, age, intelligibility, voice and speech. CONCLUSION: The judges used similar criteria in the perceptual judgment of the severity.

Determinant factors of severity rating of phonological disorder

Tema: Distúrbio fonológico. Objetivo: analisar os descritores da gravidade usados por alunos de Fonoaudiologia e fonoaudiólogos para classificar o distúrbio fonológico. Método: participaram 60 juízes com função de atribuir critérios para enquadramento de 50 sujeitos com distúrbio fonológico nas categorias de gravidade, após ouvirem suas amostras de fala. Resultados: os descritores de gravidade mais usados pelos juízes e mais aplicados aos sujeitos para justificarem o grau de gravidade foram: fonologia, idade, inteligibilidade, voz e fala. Conclusão: os juízes usaram critérios semelhantes no julgamento perceptivo da gravidade.

Methodological aspects of assessing speech intelligibility among children with impaired hearing.

OBJECTIVE: In the assessment of speech intelligibility, procedures that are easy to use, but also valid and reliable, are needed. The aim of this study was to explore the reliability and concurrent validity of two scaling methods for assessing the speech intelligibility of children with impaired hearing. MATERIAL AND METHODS: A total of 51 children aged 4-17 years with a mild to profound hearing impairment performed a naming task comprising 62 single words. Altogether, 85 inexperienced listeners, divided into 17 panels, assessed the speech production of the children. A percent correct score (for identification of the words) was obtained from every listener. The listeners were also asked to judge the overall intelligibility of each child using a visual analogue scale (VAS) and a four-point ordinal level rating scale with verbal descriptors. RESULTS: The percent correct score correlated significantly both with the VAS and the rating scale with verbal descriptors (Pearsons' coefficient 0.90 and Spearman's coefficient 0.78, respectively). Also, the VAS and the scale with verbal descriptors were significantly intercorrelated (Spearman's rho 0.85). Moderate to high correlations were usually obtained for all grades of hearing impairment, both sexes, different age groups and main communication modes. CONCLUSIONS: Especially for assessing the need for remediation of speech and in monitoring its effectiveness, a quick overall estimate of speech intelligibility can be obtained quite reliably using the above rating scales. Item identification is more time-consuming but is often needed in research and therapy planning, where acoustic and linguistic phenomena that reduce intelligibility need to be traced.

Assessing intelligibility in speakers with cleft palate: a critical review of the literature.

OBJECTIVE: A literature review was conducted in order to investigate three research questions: how is speech intelligibility being measured in speakers with cleft lip and palate? Is intelligibility adequately being distinguished from related measures such as acceptability? Has there been an increased understanding of intelligibility deficits in speakers with cleft lip and palate? Fifty-seven relevant articles published between 1960 and 1998 were included in the analysis. RESULTS: The results showed an increase in the number of articles that included a measure of intelligibility or a similar measure. Several concerns were raised as a result of the review, including the reliability and validity of measures being employed, adequate definition and differentiation of terms, and the need to determine speech and nonspeech variables contributing to reductions in intelligibility. Relevant literature on intelligibility from fields outside cleft lip and palate is reviewed, and a number of recommendations are made regarding the measurement of intelligibility in speakers with cleft lip and palate.

Direct magnitude estimation and interval scaling of pleasantness and severity in dysphonic and normal speakers.

The purpose of this study was to determine the validity of voice pleasantness and overall voice severity ratings of dysphonic and normal speakers using direct magnitude estimation (DME) and equal-appearing interval (EAI) auditory-perceptual scaling procedures. Twelve naive listeners perceptually evaluated voice pleasantness and severity from connected speech samples produced by 24 adult dysphonic speakers and 6 normal adult speakers. A statistical comparison of the two auditory-perceptual scales yielded a linear relationship representative of a metathetic continuum for voice pleasantness. A statistical relationship that is consistent with a prothetic continuum was revealed for ratings of voice severity. These data provide support for the use of either DME or EAI scales when making auditory-perceptual judgments of pleasantness, but only DME scales when judging overall voice severity for dysphonic speakers. These results suggest further psychophysical study of perceptual dimensions of voice and speech must be undertaken in order to avoid the inappropriate and invalid use of EAI scales used in the auditory-perceptual evaluation of the normal and dysphonic voice.

The effects of familiarization on intelligibility and lexical segmentation in hypokinetic and ataxic dysarthria.

This study is the third in a series that has explored the source of intelligibility decrement in dysarthria by jointly considering signal characteristics and the cognitive-perceptual processes employed by listeners. A paradigm of lexical boundary error analysis was used to examine this interface by manipulating listener constraints with a brief familiarization procedure. If familiarization allows listeners to extract relevant segmental and suprasegmental information from dysarthric speech, they should obtain higher intelligibility scores than nonfamiliarized listeners, and their lexical boundary error patterns should approximate those obtained in misperceptions of normal speech. Listeners transcribed phrases produced by speakers with either hypokinetic or ataxic dysarthria after being familiarized with other phrases produced by these speakers. Data were compared to those of nonfamiliarized listeners [Liss et al., J. Acoust. Soc. Am. 107, 3415-3424 (2000)]. The familiarized groups obtained higher intelligibility scores than nonfamiliarized groups, and the effects were greater when the dysarthria type of the familiarization procedure matched the dysarthria type of the transcription task. Remarkably, no differences in lexical boundary error patterns were discovered between the familiarized and nonfamiliarized groups. Transcribers of the ataxic speech appeared to have difficulty distinguishing strong and weak syllables in spite of the familiarization. Results suggest that intelligibility decrements arise from the perceptual challenges posed by the degraded segmental and suprasegmental aspects of the signal, but that this type of familiarization process may differentially facilitate mapping segmental information onto existing phonological categories.