Glottal Features in Vocal Assessment Following Thyroidectomy.

OBJECTIVES: Vocal dysfunction is a frequent complication following thyroidectomy that can be associated with a negative impact on patients' quality of life. Although the effect of thyroidectomy on acoustic features has been widely studied, the examination of glottal flow characteristics to assess vocal outcomes following thyroid gland surgery has not been included in empirical research, to date. The goal of our study was to evaluate early and short-term vocal outcomes following thyroidectomy based on the analysis of glottal acoustic features during speech production. STUDY DESIGN: Prospective analytical study. MATERIALS AND METHODS: We evaluated vocal outcomes in patients who underwent thyroidectomy between September 2021 and March 2022. We extracted glottal flow features from their vocal recordings preceding surgery and postoperatively at Day1 and Month1 postoperatively. The extraction of glottal features was performed using a signal processing-based approach. We extracted the following features: Open quotients (OQ1 and OQ2), Quasi-open quotient (QoQ), Closing quotient (ClQ), Amplitude quotient (AQ), Normalized Amplitude quotient (NAQ) and Speed quotients (SQ1 and SQ2). We included 39 patients. OQ2 and QoQ decreased significantly at Day1 and Month1. OQ1 and NAQ decreased significantly at Month1. ClQ remained stable at both postoperative assessments. AQ decrease was not significant at both dates. SQ1 increased at Day1 and Month1 but the change was not significant. SQ2 decreased significantly at both Day1 and Month1. OQ, QoQ, AQ, NAQ, and SQ2 did not recover at Month1. We noted that the decrease of SQ1 and SQ2 correlated significantly with the increase of the Voice Handicap Index-10 (VHI-10) at Month1. CONCLUSION: The analysis of glottal acoustic features can be a reliable modality to detect vocal changes following thyroidectomy. Thyroidectomy was associated with a vocal dysfunction that was manifested by the decrease of open, amplitude, and speed quotients. Glottal features can present a potential tool to objectively assess the effect of thyroidectomy on vocal folds movements.

Influence of Mental Training of Attentional Control on Autonomic Arousal Within the Framework of the Temporal Preparation of a Force Task.

While temporal preparation has frequently been examined through the manipulation of foreperiods, the role of force level during temporal preparation remains underexplored. In our study, we propose to manipulate mental training of attentional control in order to shed light on the role of the force level and autonomic nervous system in the temporal preparation of an action. Forty subjects, divided into mental training group (n = 20) and without mental training group (n = 20), participated in this study. The influence of the attentional control and force levels on the autonomic nervous system were measured using the skin conductance response and the heart rate variability; the accuracy of the motor responses was measured using a method derived from machine learning. Behaviorally, only the mental training group reinforced its motor and attentional control. When using short foreperiod durations and high force level, motor and attentional control decreased, consistent with the dominant sympathetic system. This resulted in an increased anticipation rate of responses with a higher reaction time compared to the long foreperiods duration and low force level, in which the reaction time significantly decreased, with enhancement of the expected force level, showing consistency with the dominant parasympathetic system. Interestingly, results revealed a predictive relationship between the sympathovagal balance and motor and attentional control during the long foreperiods and low force level. Finally, results demonstrate that attentional mental training leads to the reinforcement of interactions between the autonomic nervous system and attentional processes which are involved in the temporal preparation of a force task.

Analysis of Voice Quality After Thyroid Surgery.

OBJECTIVES: Voice changes are a common complication after a thyroidectomy, which is a surgical procedure involving partial or total removal of the thyroid gland. The main objective of this work is to examine the possible voice disorders after thyroid surgery. More precisely, it is an investigation of partial and total thyroidectomy, as well as the effects that cancerous and noncancerous thyroid glands can have regarding postsurgical vocal and their association with age and gender. METHODS: Patients were evaluated using acoustic voice parameters, including harmonics-to-noise ratio (HNR), fundamental frequency (F0), jitter, speaker phonation frequency (SPF) range, cepstral peak prominence (CPP), maximum phonational frequency range (MPFR), and shimmer at the preoperative stage and postoperatively at the 1 day, and first-month stages. RESULTS: Results demonstrated a significant change in F0 parameters, SPF range, and CPP feature 1 month after surgery, depending on the type of thyroidectomy and thyroid pathology. No significant changes were observed in the HNR, shimmer, and jitter features. Age was associated with the CPP parameter in the entire sample. In contrast, the MPFR parameter was also related to the type of thyroidectomy in the entire sample. However, maximum F0 was significantly associated with the type of thyroidectomy, specifically in the female sample. CONCLUSIONS: Results indicated that a thyroidectomy can have a negative impact on voice quality. The age and type of thyroidectomy performed are not responsible for this change. Potentially this change can be due to factors such as nerve damage or the subjects' experience, such as job, anxiety, and their physical condition, as well as treatments they may have undergone before thyroidectomy. Further efforts are needed to fully understand the background of voice changes after thyroidectomy.

A Spectral-Based Approach for BCG Signal Content Classification.

This paper has two objectives: the first is to generate two binary flags to indicate useful frames permitting the measurement of cardiac and respiratory rates from Ballistocardiogram (BCG) signals-in fact, human body activities during measurements can disturb the BCG signal content, leading to difficulties in vital sign measurement; the second objective is to achieve refined BCG signal segmentation according to these activities. The proposed framework makes use of two approaches: an unsupervised classification based on the Gaussian Mixture Model (GMM) and a supervised classification based on K-Nearest Neighbors (KNN). Both of these approaches consider two spectral features, namely the Spectral Flatness Measure (SFM) and Spectral Centroid (SC), determined during the feature extraction step. Unsupervised classification is used to explore the content of the BCG signals, justifying the existence of different classes and permitting the definition of useful hyper-parameters for effective segmentation. In contrast, the considered supervised classification approach aims to determine if the BCG signal content allows the measurement of the heart rate (HR) and the respiratory rate (RR) or not. Furthermore, two levels of supervised classification are used to classify human-body activities into many realistic classes from the BCG signal (e.g., coughing, holding breath, air expiration, movement, et al.). The first one considers frame-by-frame classification, while the second one, aiming to boost the segmentation performance, transforms the frame-by-frame SFM and SC features into temporal series which track the temporal variation of the measures of the BCG signal. The proposed approach constitutes a novelty in this field and represents a powerful method to segment BCG signals according to human body activities, resulting in an accuracy of 94.6%.

The effect of the preparation instruction on the functional connectivity between forearm muscles during movement's initiation.

This study investigates the effect of preparation warning on the functional connectivity between forearm muscles during movement's initiation. The Normalized Mutual Information (NMI) is the used indicator. It is calculated for muscle pairs activated during a handgrip exercice. They are innervated by the same nerve or by different nerves. Results show that: i) NMI is more important when muscles pairs are stimulated by the same nerve during both preparation and motor activities. ii) NMI is higher during preparation comparing to motor activity. iii) The functional connectivity during contraction's beginning increases when a preparation warning is given. We conclude that muscles put together their effort to initiate the movement especially when participants prepare in advance their activity.