Towards Evaluating Pitch-Related Phonation Function in Speech Communication Using High-Density Surface Electromyography

Pitch, as a sensation of the sound frequency, is a crucial attribute toward constructing a natural voice for communication. Producing intelligible sounds with normal pitches depend on substantive interdependencies among facial and neck muscles. Clarifying the interrelations between the pitches and the corresponding muscular activities would be helpful for evaluating the pitch-related phonating functions, which would play a significant role both in training pronunciation and in assessing dysphonia. In this study, the speech signals and the high-density surface electromyography (HD sEMG) signals were synchronously acquired when phonating [a:], [i:], and [ә:] vowels with increasing pitches, respectively. The HD sEMG energy maps were constructed based on the root mean square values to visualize spatiotemporal characteristics of facial and neck muscle activities. Normalized median frequency (nMF) and root-mean square (nRMS) were correspondingly extracted from the speech and sEMG recordings to quantitatively investigate the correlations between sound frequencies and myoelectric characteristics. The results showed that the frame-wise energy maps built from sEMG recordings presented that the muscle contraction strength increased monotonously across pitch-rising, with left-right symmetrical distribution for the face/neck. Furthermore, the nRMS increased at a similar rate to the nMF when there were rising pitches, and the two parameters had a significant correlation across different vowel tasks [(a:) (0.88 ± 0.04), (i:) (0.89 ± 0.04), and (ә:) (0.87 ± 0.05)]. These findings suggested the possibility of utilizing muscle contraction patterns as a reference for evaluating pitch-related phonation functions. The proposed method could open a new window for developing a clinical approach for assessing the muscular functions of dysphonia

Surface electromyographic (sEMG) activity of the suprahyoid and sternocleidomastoid muscles in pitch and loudness control

Purpose: This study set out to determine the contributions of the suprahyoid and sternocleidomastoid (SCM) muscles in changing pitch and loudness during phonation among vocally healthy populations.Method: Thirty-nine participants were first recruited, and twenty-nine of them who passed the screening test (Voice Handicap Index [VHI]-10 score ≤11, auditory-perceptual voice rating score ≤2) were finally selected (mean age = 28.2 years). All participants were measured for their surface electromyographic (sEMG) activity collected from the bilateral suprahyoid and SCM muscles when producing the vowel /a/, /i/, and /u/ in natural (baseline) and at different pitch (+3, +6, -3, -6 semitones) and loudness (+5, +10, −5 dB) levels. Linear mixed-effects models were performed to determine the influencing factors on the root-mean-square percentage of maximal voluntary contraction (RMS %MVC) value of the sEMG signals.Results: Compared with the baseline, a significant decrease of RMS %MVC was found in the suprahyoid muscles during overall phonations of lower pitches (−3 and −6 semitones) and loudness (−5 dB). However, no significant change was detected when producing speech at higher pitch (+3 and +6 semitones) and loudness (+5 and +10 dB) levels. Among the three vowels, /i/ demonstrated significantly higher RMS %MVC than those of /a/ and /u/. The SCM muscles, however, did not show any significant change in the RMS %MVC values among different vowels in relation to the pitch and loudness changes. When the muscles were compared across the two sides, significantly higher RMS %MVC was found in the right side of the suprahyoid (in pitch and loudness control) and SCM (in pitch control) when compared to the left side.Conclusions: The suprahyoid muscle activities were significantly decreased when producing lower pitches and intensities compared to the natural baselines. The production of sustained /i/ required significantly more suprahyoid muscle activities than those of /a/ and /u/. The SCM muscles did not show much sEMG activity in any of the pitch and loudness levels, which could be used potentially as the calibration or normalization of peri-laryngeal sEMG measurement. The findings also showed a tendency for bilateral asymmetry in the use of suprahyoid and SCM muscles

Numerical Study of Laryngeal Control of Phonation using Realistic Finite Element Models of a Canine Larynx

While many may take it for granted, the human voice is an incredible feat. An average person can produce a great variety of voices and change voice characteristics agilely even without formal training. Last several decades of research has established that the production of voice is largely a mechanical process: i.e., the sustained vibration of the vocal folds driven by the glottal air flow. Since one only has a single pair of vocal folds, the versatility comes with the ability to change the mechanical status of the vocal folds, including vocal fold length and thickness, tension, and level of adduction, through activation of the laryngeal muscles. However, the relationship between laryngeal muscle activity and the characteristics of voice is not well understood due to limitations in experimental observation and simplifications in modelling and simulations. The science is still far behind the art. The current research aims to investigate first the relationship between laryngeal muscle activation and the posture of the vocal folds and second the relationship between voice source characteristics and vocal fold mechanical status using more comprehensive numerical models and simulations, thus improving the understanding of the roles of each laryngeal muscle in voice control. To do so, (1) the mechanics involved in vocal fold posturing and vibration, especially muscle contraction; (2) the realistic anatomical structure of the larynx must be considered properly. To achieve this goal, a numerical model of the larynx as realistic as possible was built. The geometry of the laryngeal components was reconstructed from high resolution MRI (Magnetic Resonance Imaging) data of an excised canine larynx, which makes more accurate the representation of the muscles and their sub-compartments, cartilages, and other important anatomical features of the larynx. A previously proposed muscle activation model was implemented in a 3D finite element package and applied to the larynx model to simulate the action of laryngeal muscles. After validation of the numerical model against experimental data, extensive parametric studies involving different combination of muscle activations were conducted to investigate how the voice source is controlled with laryngeal muscles. In the course of this study, some work was done to couple the same finite element tool with a Genetic Algorithm program to inversely determine model parameters in biomechanical models. The method was applied in a collaborated study on shape changes of a fish fin during swimming. This study is presented as a separate chapter at the end of this thesis. The method has potential application in determining parameters in vocal fold models and optimizing clinical vocal fold procedures. This thesis is essentially an assembly of the papers published by the author during the doctoral study, with the addition of an introductory chapter. Chapter 1 reviews the overall principles of voice production, the biomechanical basis of voice control, and past studies on voice control with a focus on the fundamental frequency. Chapter 2 describes the major numerical methods employed in this research with an emphasis on the finite element method. The muscle activation model is also described in this chapter. Chapter 3 describes the building of the larynx model from MRI data and its partial validation. Chapter 4 presents the application of the larynx model to posturing studies, including parametric activation of muscle groups and specific topics related to vocal fold posturing. Chapter 5 describes the change of vocal fold vibration dynamics under the influence of the interaction of the cricothyroid muscle and the thyroarytenoid muscle. The Flow-structure interaction simulations was realized by coupling the larynx model to a simple Bernoulli flow model and a two-stage simulation technique. Chapter 6 concludes the current thesis study. Suggestions for future studies are proposed. Chapter 7 is an independent study that is not related to voice control. It describes a numerical framework that inversely determines and validates model parameters of biomechanical models. The application of the proposed framework to a finite element model of a fish fin is presented

The glottalic consonants of Hausa.

This thesis is concerned with the examination of the glottalic consonants of Hausa, a Chadic language spoken in northern Nigeria, Niger, Cameroon, Togo and Ghana. The glottalic consonants constitute a set of phonemes in the language whose historical and phonetic properties merit further investigation. The study is laid out in three parts. Part one (Chapters 1, 2 and 3) is the historical section. Here, a general overview of the Hausa language is given. Also discussed are several specific points made by pioneers of the genetic classification of Chadic within Afroasiatic and the reconstruction of glottalic consonants in both Chadic and Afroasiatic. The discussion here is not new but presents a summary of the literature. Hausa native words that have glottalic consonants are compared with possible cognates from other related Chadic languages from West, Central and East branches of Chadic and also from other Afroasiatic languages. Part two (Chapters 4 and 5) of the study concerns the investigation of phonation types in general. Chapter 4 gives a short account of the larynx, the mechanism of the vocal fold vibration and classification of phonation types. Chapter 5 is devoted to a review of instrumental techniques used in voice measurement. Part three (Chapter 6, the instrumental section) presents and discusses the results of a detailed electro- laryngographic analysis of the activity of the behaviour of the vocal folds in the production of the glottalic consonants and their non-glottalic counterparts as observed in the speech of educated native speakers of the language. The chapter begins with a review of the literature reporting early instrumental and non-instrumental studies of the segmental phonemes of the language. This is followed by a description of the techniques used to record, display and annotate both speech pressure and laryngographic waveforms. Both qualitative and quantitative analysis of the waveforms are presented. The most important parameter in the quantitative analysis is estimated open quotient (OQ) derived from the Lx waveforms measurements of Fundamental Frequency, duration and Voice Onset Time are also given. The chapter concludes by presenting the results of the experiment: 1 OQ increases in anticipation of plain voiceless consonants, and is relatively high at the consonantal release; 2 OQ decreases in anticipation of laryngealized consonants including the glottal stop (for most speakers) and less sharply for the ejectives; 3 OQ remains approximately at the speaker's modal value for the plain voiced consonants; 4 The laryngealized segments tend to lower pitch at the left of the consonant; and 5 They also tend to be longer than their plain counterparts

Models and Analysis of Vocal Emissions for Biomedical Applications

The International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA) came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy. This edition celebrates twenty years of uninterrupted and succesfully research in the field of voice analysis

Models and Analysis of Vocal Emissions for Biomedical Applications

The International Workshop on Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA) came into being in 1999 from the particularly felt need of sharing know-how, objectives and results between areas that until then seemed quite distinct such as bioengineering, medicine and singing. MAVEBA deals with all aspects concerning the study of the human voice with applications ranging from the neonate to the adult and elderly. Over the years the initial issues have grown and spread also in other aspects of research such as occupational voice disorders, neurology, rehabilitation, image and video analysis. MAVEBA takes place every two years always in Firenze, Italy

A study of voice quality in a group of irradiated laryngeal cancer patients tumour stages T1 and T2.

This is a longitudinal study of voice quality in a group of 35 patients irradiated for early vocal fold tumours, stages T1 and T2. Electrolaryngograph (ELG) based analyses were used to obtain objective measurements of speaking fundamental frequency parameters over a wide range of time intervals following radiotherapy. Lx waveforms were also analysed. Perceptual evaluation of voice quality and patients' self assessments of their experience of vocal symptoms and limitations in vocal function after radiotherapy, were carried out. The relationship between perceptual and self assessment parameters and objective voice quality measurements was determined. A few patients underwent periods of voice therapy. A comparison is made of their voice measurements before and after therapy intervention with a group of patients, who did not receive voice therapy. The findings in this study show that, contrary to some early reports that the voice returns to normal in the majority of patients after radiotherapy, most patients' show evidence of residual abnormal voice quality and symptoms as measured and as rated by clinicians and by patients themselves. The majority of patients do not consider these a major problem, however. Evidence is presented of the beneficial effect of voice therapy to help patients compensate for the inevitable tissue damage caused by radiotherapy to the larynx. Electrolaryngograph generated objective measures and Lx waveforms proved sensitive, reliable and clinically applicable for objective voice analysis

A study of voice production in normal and dysphonic subjects

The aims of the research described in this thesis were to investigate some of the factors involved in voice production, and to develop some of the techniques employed, to a stage at which they could be used clinically to assess phonatory function. Available techniques for assessing vocal performance were completely subjective, and, thus, there was a great need to provide objective means of measuring the degrees of vocal dysfunction of the many patients attending the Speech Therapy Department. In: CHAPTER 1, the vocal tract and musculature of the larynx and vocal folds are described. The Myoelastic-Aerodynamic theory of vocal fold vibration is briefly discussed, and a review of some of the relevant literature is given. The instrumentation used in the study is detailed in CHAPTER 2. The maintenance and control of air flow is of prime importance to voice production, and in CHAPTER 3, aerodynamic measurements are utilized in providing two series of tests which can be used to assess phonatory function-. These are now used routinely in the Speech Therapy Department. The production of voiced sounds depends upon the interruption of the air supply from the lungs by the regular vibration of the vocal folds. Thus the frequency spectra of voiced sounds, and in particular of vowel sounds, consist of harmonic series, with regular frequency components. The frequency analysis of vowel sounds is described in CHAPTER 4, and the presence of abnormal components related to dysphonic conditions. The results obtained from an assessment based on spectral analysis (due to Yanagihara) are compared to those obtained from the aerodynamic assessment developed in CHAPTER 3, with the latter assessment proving of greater value as a routine clinical technique. The vibratory pattern of the vocal folds is studied in CHAPTER 5 using the non-invasive laryngo-graph technique. The period of major excitation of the vocal tract, i.e. the closing phase of the vocal fold vibration, is related to certain properties of the spectrum of the laryngograph waveform, namely the spectral gradient and also the presence of fine structure in the spectrum. Abnormal spectral components in the voice spectra are shown to originate from the vocal fold vibratory pattern, and a simple model of the vocal folds is used to explain some of the phenomena. In CHAPTER 6 the control of a sustained vowel phonation is discussed, and the relationships between air flow rate, sound level and the vibratory pattern of the vocal folds are studied. In CHAPTER 7 the electromyographic activity associated with the lip musculature, during the production of a consonant - vowel - consonant syllable, is- studied. The differences in the outputs obtained using different electrode sites and configurations are explained, and the measured activity attributed to different muscle groups by a process of spatial mapping. The main results of the experiments are summarized in CHAPTER 8. This research has led to a greater understanding of the processes involved in voice production, and also to the development of objective techniques which can be used directly in the assessment of dysphonic patients

Respiratory Control: Central and Peripheral Mechanisms

Understanding of the respiratory control system has been greatly improved by technological and methodological advances. This volume integrates results from many perspectives, brings together diverse approaches to the investigations, and represents important additions to the field of neural control of breathing. Topics include membrane properties of respiratory neurons, in vitro studies of respiratory control, chemical neuroanatomy, central integration of respiratory afferents, modulation of respiratory pattern by peripheral afferents, respiratory chemoreception, development of respiratory control, behavioral control of breathing, and human ventilatory control. Forty-seven experts in the field report research and discuss novel issues facing future investigations in this collection of papers from an international conference of nearly two hundred leading scientists held in October 1990. This research is of vital importance to respiratory physiologists and those in neurosciences and neurobiology who work with integrative sensory and motor systems and is pertinent to both basic and clinical investigations. Respiratory Control is destined to be widely cited because of the strength of the contributors and the dearth of similar works. The four editors are affiliated with the University of Kentucky: Dexter F. Speck is associate professor of physiology and biophysics, Michael S. Dekin is assistant professor of biological sciences, W. Robert Revelette is research scientist of physiology and biophysics, and Donald T. Frazier is professor and chairman of physiology and biophysics. Experts in the field report current research and discuss novel issues facing future investigations. —SciTech Book Newshttps://uknowledge.uky.edu/upk_biology/1002/thumbnail.jp