Correlations between swallowing function and acoustic vowel space in stroke patients with dysarthria

The Study of Speech Acoustic Characteristics of Elderly Individuals with Presbyphagia in Ningbo, China

The feasibility of using acoustic parameters to predict presbyphagia has been preliminarily confirmed. Considering that age and gender can influence the results of acoustic parameters, this study aimed to further explore the specific effects of age and gender on acoustic parameter analysis of the elderly population over 60 years old with presbyphagia. A total of 45 participants were enrolled and divided into three groups (60-69 years old, 70-79 years old, and 80-89 years old). Acoustic parameters, including maximum phonation time, first to third formant frequencies (F1-F3) of /a/, /i/, and /u/, oral diadochokinesis, the acoustic vowel space, and laryngeal diadochokinesis (LDDK), were extracted and calculated. Two-way analysis of variance was used to analyze the correlations between acoustic parameters and age and gender. The result indicates that /hʌ/ LDDK rate had significant differences in age groups, presenting the 80-89 age group being significantly slower than the 60-69 age group. F1/a/, F2/a/, F2/i/, F3/i/, and F2i/F2u differed systematically between genders, with males being lower and smaller than females. Changes that were consistent with /hʌ/ LDDK regularity, confirmed by greater regularity in females. No significant differences were observed for other acoustic parameters. No significant interactions were revealed. According to the preliminary data, we hypothesized that respiratory capacity and control during vocal fold abduction weaken with aging. This highlights the importance of continuously monitoring the respiratory impact on swallowing function in elderly individuals. Additionally, gender influenced several acoustic parameters, indicating the necessity to differentiate between genders when assessing presbyphagia using acoustic parameters, especially focusing on swallowing function in elderly males in Ningbo.

Digital markers of motor speech impairments in spontaneous speech of patients with ALS-FTD spectrum disorders

OBJECTIVE

To evaluate automated digital speech measures, derived from spontaneous speech (picture descriptions), in assessing bulbar motor impairments in patients with ALS-FTD spectrum disorders (ALS-FTSD).

METHODS

Automated vowel algorithms were employed to extract two vowel acoustic measures: vowel space area (VSA), and mean second formant slope (F2 slope). Vowel measures were compared between ALS with and without clinical bulbar symptoms (ALS + bulbar (n = 49, ALSFRS-r bulbar subscore: x¯ = 9.8 (SD = 1.7)) vs. ALS-nonbulbar (n = 23), behavioral variant frontotemporal dementia (bvFTD, n = 25) without a motor syndrome, and healthy controls (HC, n = 32). Correlations with bulbar motor clinical scales, perceived listener effort, and MRI cortical thickness of the orobuccal primary motor cortex (oral PMC) were examined. We compared vowel measures to speaking rate, a conventional metric for assessing bulbar dysfunction.

RESULTS

ALS + bulbar had significantly reduced VSA and F2 slope than ALS-nonbulbar (|d|=0.94 and |d|=1.04, respectively), bvFTD (|d|=0.89 and |d|=1.47), and HC (|d|=0.73 and |d|=0.99). These reductions correlated with worse bulbar clinical scores (VSA: R = 0.33, p = 0.043; F2 slope: R = 0.38, p = 0.011), greater listener effort (VSA: R=-0.43, p = 0.041; F2 slope: p > 0.05), and cortical thinning in oral PMC (F2 slope: β = 0.0026, p = 0.017). Vowel measures demonstrated greater sensitivity and specificity for bulbar impairment than speaking rate, while showing independence from cognitive and respiratory impairments.

CONCLUSION

Automatic vowel measures are easily derived from a brief spontaneous speech sample, are sensitive to mild-moderate stage of bulbar disease in ALS-FTSD, and may present better sensitivity to bulbar impairment compared to traditional assessments such as speaking rate.

Digital markers of motor speech impairments in natural speech of patients with ALS-FTD spectrum disorders

Background and objectives

Patients with ALS-FTD spectrum disorders (ALS-FTSD) have mixed motor and cognitive impairments and require valid and quantitative assessment tools to support diagnosis and tracking of bulbar motor disease. This study aimed to validate a novel automated digital speech tool that analyzes vowel acoustics from natural, connected speech as a marker for impaired articulation due to bulbar motor disease in ALS-FTSD.

Methods

We used an automatic algorithm called Forced Alignment Vowel Extraction (FAVE) to detect spoken vowels and extract vowel acoustics from 1 minute audio-recorded picture descriptions. Using automated acoustic analysis scripts, we derived two articulatory-acoustic measures: vowel space area (VSA, in Bark 2 ) which represents tongue range-of-motion (size), and average second formant slope of vowel trajectories (F2 slope) which represents tongue movement speed. We compared vowel measures between ALS with and without clinically-evident bulbar motor disease (ALS+bulbar vs. ALS-bulbar), behavioral variant frontotemporal dementia (bvFTD) without a motor syndrome, and healthy controls (HC). We correlated impaired vowel measures with bulbar disease severity, estimated by clinical bulbar scores and perceived listener effort, and with MRI cortical thickness of the orobuccal part of the primary motor cortex innervating the tongue (oralPMC). We also tested correlations with respiratory capacity and cognitive impairment.

Results

Participants were 45 ALS+bulbar (30 males, mean age=61±11), 22 ALS-nonbulbar (11 males, age=62±10), 22 bvFTD (13 males, age=63±7), and 34 HC (14 males, age=69±8). ALS+bulbar had smaller VSA and shallower average F2 slopes than ALS-bulbar (VSA: | d |=0.86, p =0.0088; F2 slope: | d |=0.98, p =0.0054), bvFTD (VSA: | d |=0.67, p =0.043; F2 slope: | d |=1.4, p <0.001), and HC (VSA: | d |=0.73, p =0.024; F2 slope: | d |=1.0, p <0.001). Vowel measures declined with worsening bulbar clinical scores (VSA: R=0.33, p =0.033; F2 slope: R=0.25, p =0.048), and smaller VSA was associated with greater listener effort (R=-0.43, p =0.041). Shallower F2 slopes were related to cortical thinning in oralPMC (R=0.50, p =0.03). Neither vowel measure was associated with respiratory nor cognitive test scores.

Conclusions

Vowel measures extracted with automatic processing from natural speech are sensitive to bulbar motor disease in ALS-FTD and are robust to cognitive impairment.

Establishment of a Multi-parameter Evaluation Model for Risk of Aspiration in Dysphagia: A Pilot Study

It's difficult for clinical bedside evaluations to accurately determine the occurrence of aspiration in patients. Although VFSS and FEES are the gold standards for clinical diagnosis of dysphagia, which are mainly used to evaluate people at high risk of dysphagia found by bedside screening, the operation is complicated and time-consuming. The aim of this pilot study was to present an objective measure based on a multi-parameter approach to screen for aspiration risk in patients with dysphagia. Objective evaluation techniques based on speech parameters were used to assess the oral motor function, vocal cord function, and voice changes before and after swallowing in 32 patients with dysphagia (16 low-risk aspiration group, 16 high-risk aspiration group). Student's t test combined with stepwise logistic regression were used to determine the optimal index. The best model consists of three parameters, and the equation is: logit(P) = - 3.824 - (0.504 × maximum phonation time) + (0.008 × second formant frequency of /u/) - 0.085 × (fundamental frequency difference before and after swallowing). An additional eight patients with dysphagia were randomly selected as the validation group of the model. When applied to validation, this model can accurately identify the risk of aspiration in 87.5% of patients, and the sensitivity is as high as 100%. Therefore, it has certain clinical practical value that may help clinicians to assess the risk of aspiration in patients with dysphagia, especially for silent aspiration.

Destruction of Vowel Space Area in Patients with Dysphagia after Stroke

Dysphagia is associated with dysarthria in stroke patients. Vowel space decreases in stroke patients with dysarthria; destruction of the vowel space is often observed. We determined the correlation of destruction of acoustic vowel space with dysphagia in stroke patients. Seventy-four individuals with dysphagia and dysarthria who had experienced stroke were enrolled. For /a/, /ae/, /i/, and /u/ vowels, we determined formant parameter (it reflects vocal tract resonance frequency as a two-dimensional coordinate point), formant centralization ratio (FCR), and quadrilateral vowel space area (VSA). Swallowing function was assessed using the videofluoroscopic dysphagia scale (VDS) during videofluoroscopic swallowing studies. Pearson's correlation and linear regression were used to determine the correlation between VSA, FCR, and VDS. Subgroups were created based on VSA; vowel space destruction groups were compared using ANOVA and Scheffe's test. VSA and FCR were negatively and positively correlated with VDS, respectively. Groups were separated based on mean and standard deviation of VSA. One-way ANOVA revealed significant differences in VDS, FCR, and age between the VSA groups and no significant differences in VDS between mild and moderate VSA reduction and vowel space destruction groups. VSA and FCR values correlated with swallowing function. Vowel space destruction has characteristics similar to VSA reduction at a moderate-to-severe degree and has utility as an indicator of dysphagia severity.

Immediate effect of different exercises in the vocal space of women with and without vocal nodules

PURPOSE

To investigate the immediate effect of voiced tongue vibration (VSL), high-resistance straw in the air (CAR), and overarticulation (OA) on the vocal space of vocally healthy women (MVS) and with vocal nodules (MNV).

METHODS

12 women participated in the MNV and 12 women in the MVS, allocated to perform the vocal exercises of VSL, CAR, and OA. Each participant performed only one of the three proposed exercises, for 5 minutes, preceded and followed by recording a sequence of vehicle sentences for extracting formants (F1 and F2) from the vowel segments [a, i, u]. The vowel space was analyzed through the differences between the measures of the formants of the vowels.

RESULTS

we observed a reduction of F1 in the interval [a]-[i] and [i]-[u] and of F2 between the vowels [a]-[u] and [i]-[u] in the MVS, after performing the CAR. In MNV, we observed a reduction of F2 in the interval [a]-[i] after VSL. In the intergroup analysis, there were higher F1 values between the intervals of the vowels [a]-[i] and [i]-[u] in the MVS, before performing the CAR, and after exercise only in the interval [a]-[i]. A higher value of F1 and F2 was observed in the interval between the vowels [i]-[u] in the MNV after VSL.

CONCLUSION

The VSL exercise reduced the vowel space in MNV women. CAR reduced the vocal space of women in the MVS. The MNV had a smaller vowel space compared to the MVS before and after the CAR. We observed a reduction in the vowel space in the MNV compared to the MNV after the VSL exercise.

Immediate effect of different exercises in the vocal space of women with and without vocal nodules

ABSTRACT Purpose To investigate the immediate effect of voiced tongue vibration (VSL), high-resistance straw in the air (CAR), and overarticulation (OA) on the vocal space of vocally healthy women (MVS) and with vocal nodules (MNV). Methods 12 women participated in the MNV and 12 women in the MVS, allocated to perform the vocal exercises of VSL, CAR, and OA. Each participant performed only one of the three proposed exercises, for 5 minutes, preceded and followed by recording a sequence of vehicle sentences for extracting formants (F1 and F2) from the vowel segments [a, i, u]. The vowel space was analyzed through the differences between the measures of the formants of the vowels. Results we observed a reduction of F1 in the interval [a]-[i] and [i]-[u] and of F2 between the vowels [a]-[u] and [i]-[u] in the MVS, after performing the CAR. In MNV, we observed a reduction of F2 in the interval [a]-[i] after VSL. In the intergroup analysis, there were higher F1 values between the intervals of the vowels [a]-[i] and [i]-[u] in the MVS, before performing the CAR, and after exercise only in the interval [a]-[i]. A higher value of F1 and F2 was observed in the interval between the vowels [i]-[u] in the MNV after VSL. Conclusion The VSL exercise reduced the vowel space in MNV women. CAR reduced the vocal space of women in the MVS. The MNV had a smaller vowel space compared to the MVS before and after the CAR. We observed a reduction in the vowel space in the MNV compared to the MNV after the VSL exercise.

Association between phonation and the vowel quadrilateral in patients with stroke: A retrospective observational study

Articulation disorder is associated with impaired control of respiration and speech organ movement. There are many cases of dysarthria and dysphonia in stroke patients. Dysphonia adversely affects communication and social activities, and it can interfere with everyday life. The purpose of this study is to assess the association between phonation abilities and the vowel quadrilateral in stroke patients.The subjects were stroke patients with pronunciation and phonation disorders. The resonance frequency was measured for the 4 corner vowels to measure the vowel space area (VSA) and formant centralization ratio (FCR). Phonation ability was evaluated by the Dysphonia Severity Index (DSI) and maximal phonation time (MPT) through acoustic evaluation for each vowel. Pearsons correlation analysis was performed to confirm the association, and multiple linear regression analysis was performed between variables.The correlation coefficients of VSA and MPT/u/ were 0.420, VSA and MPT/i/ were 0.536, VSA and DSI/u/ were 0.392, VSA and DSI /i/ were 0.364, and FCR and DSI /i/ were -0.448. Multiple linear regression analysis showed that VSA was a factor significantly influencing MPT/u/ (β = 0.420, P = .021, R = 0.147), MPT/i/ (β = 0.536, P = .002, R = 0.262), DSI/u/ (β = 0.564, P = .045, R = 0.256), and DSI/i/ (β = 0.600, P = .03, R = 0.302).The vowel quadrilateral can be a useful tool for evaluating the phonation function of stroke patients.