Neuromechanical Modelling of Articulatory Movements from Surface Electromyography and Speech Formants

Abstract

Speech articulation is produced by the movements of muscles in the larynx, pharynx, mouth and face. Therefore speech shows acoustic features as formants which are directly related with neuromotor actions of these muscles. The first two formants are strongly related with jaw and tongue muscular activity. Speech can be used as a simple and ubiquitous signal, easy to record and process, either locally or on e-Health platforms. This fact may open a wide set of applications in the study of functional grading and monitoring neurodegenerative diseases. A relevant question, in this sense, is how far speech correlates and neuromotor actions are related. This preliminary study is intended to find answers to this question by using surface electromyographic recordings on the masseter and the acoustic kinematics related with the first formant. It is shown in the study that relevant correlations can be found among the surface electromyographic activity (dynamic muscle behavior) and the positions and first derivatives of the first formant (kinematic variables related to vertical velocity and acceleration of the joint jaw and tongue biomechanical system). As an application example, it is shown that the probability density function associated to these kinematic variables is more sensitive than classical features as Vowel Space Area † †

A Neuromotor to Acoustical Jaw-Tongue Projection Model With Application in Parkinson’s Disease Hypokinetic Dysarthria

“…The differentiation between both groups is of most interest to assess HD by telemonitoring devices recording speech remotely. The validation of this possibility has been already studied using acoustic estimates only (Gómez et al, 2017(Gómez et al, , 2019a, but a wider study using both methods and ECMF is still pending.…”

Acoustic to kinematic projection in Parkinson’s disease dysarthria

“…The present study is based on a simplified jaw-tongue articulation model [16] which is known to be representative of PD dysarthria [18]. It allows to create a relationship between acoustic and kinematic variables relating the first two formants F={F1, F2} to the horizontal and vertical coordinates S={xr, yr} of the joint Jaw-Tongue Reference Point (PrJT) in the sagittal plane This point represents the center of moments of the biomechanical system integrated by the maxillary bone, tongue and facial tissues associated [17] (see Figure 1).…”

“…This led to further exploratory work, were the relationships between sEMG, accelerometry and Speech were investigated [15]. After an in-depth study of the affectations of PD on these biometric signals [16], the conclusions were applied to the characterization of PD hypokinetic dysarthria [17], [18].…”

Acoustic Analysis of Phonation in Children With Smith–Magenis Syndrome

“…More recent studies have proposed less conventional measures related to the kinematics of the phono-articulatory organs. One such measure is absolute kinematic velocity (AKV), which is associated with the myoelectric activity of certain facial muscles that move to the jaw, tongue, and lips ( Mekyska et al, 2015 ; Gómez-Vilda et al, 2019a , b ). The AKV has also been used to measure the articulation stability during sustained vowels emissions and allows to observe how much the first two formants fluctuate during the prolonged sustain of a vowel (usually an /a/), which leads to an analysis of the degree of articulatory position stability ( Gómez-Vilda et al, 2019b ).…”