Vocal Tract Configurations of Professional Operatic Singers During Sustained Phonation.

Objectives: In voice production, interactions occur between the oscillating vocal folds, the respiratory system, and the vocal tract. However, it is not yet sufficiently understood how the respiratory system could affect the vocal tract configuration. It is hypothesized that a reduction in tracheal pull, caused by decreasing lung volume, along with shifts in dominant exhalation forces (from inspiratory to expiratory muscles), leads to a larynx elevation with shortening of the vocal tract tube, and consecutively, articulatory adjustments to preserve consistent sound quality.

Investigation Methods for Vocal Onset-A Historical Perspective.

The topic of phonation onset gestures is of great interest to singers, acousticians, and voice physiologists alike. The vocal pedagogue and voice researcher Manuel Garcia, in the mid-19th century, first coined the term "coup de la glotte". Given that Garcia defined the process as "a precise articulation of the glottis that leads to a precise and clean tone attack", the term can certainly be linked to the concept of "vocal onset" as we understand it today.

Articulatory and acoustic differences between lyric and dramatic singing in Western classical music.

Within the realm of voice classification, singers could be sub-categorized by the weight of their repertoire, the so-called "singer's Fach." However, the opposite pole terms "lyric" and "dramatic" singing are not yet well defined by their acoustic and articulatory characteristics. Nine professional singers of different singers' Fach were asked to sing a diatonic scale on the vowel /a/, first in what the singers considered as lyric and second in what they considered as dramatic.

Dynamic changes of vocal tract dimensions with sound pressure level during messa di vocea).

The messa di voce (MdV), which consists of a continuous crescendo and subsequent decrescendo on one pitch is one of the more difficult exercises of the technical repertoire of Western classical singing. With rising lung pressure, regulatory adjustments both on the level of the glottis and the vocal tract are required to keep the pitch stable. The dynamic changes of vocal tract dimensions with the bidirectional variation of sound pressure level (SPL) during MdV were analyzed by two-dimensional real-time magnetic resonance imaging (25 frames/s) and synchronous audio recordings in 12 professional singer subjects.

Articulatory and Phonatory Precision When Singing Staccato at Different Speeds.

Introduction: Vocal tract adjustments are important for resonatory modification of the voice and also with respect to interactions concerning the voice source production. It is not clear, however, how fast, separated notes (staccato) influence vocal tract adjustments.

Material And Methods: Twelve professional singers (four sopranos, three mezzo-sopranos, three tenors, and two baritones/basses) were recorded with dynamic real-time 2D-magnetic resonance imaging (MRI) with 25 fps singing a scale in legato and different staccato speeds (60, 120, 180, and 240 bps).

Voice efficiency for different voice qualities combining experimentally derived sound signals and numerical modeling of the vocal tract.

Concerning voice efficiency considerations of different singing styles, from western classical singing to contemporary commercial music, only limited data is available to date. This single-subject study attempts to quantify the acoustic sound intensity within the human glottis depending on different vocal tract configurations and vocal fold vibration. Combining Finite-Element-Models derived from 3D-MRI data, audio recordings, and electroglottography (EGG) we analyzed vocal tract transfer functions, particle velocity and acoustic pressure at the glottis, and EGG-related quantities to evaluate voice efficiency at the glottal level and resonance characteristics of different voice qualities according to Estill Voice Training.

Differences of respiratory kinematics in female and male singers - A comparative study using dynamic magnetic resonance imaging.

Breath control is an important factor for singing voice production, but pedagogic descriptions of how a beneficial movement pattern should be performed vary widely and the underlying physiological processes are not understood in detail. Differences in respiratory movements during singing might be related to the sex of the singer. To study sex-related differences in respiratory kinematics during phonation, 12 singers (six male and six female) trained in the Western classical singing tradition were imaged with dynamic magnetic resonance imaging.

Vocal Behavior of Teachers Reading with Raised Voice in a Noisy Environment.

(1) Objective: Teaching is a particularly voice-demanding occupation. Voice training provided during teachers' education is often insufficient and thus teachers are at risk of developing voice disorders. Vocal demands during teaching are not only characterized by speaking for long durations but also by speaking in noisy environments.

Investigation of resonance strategies of high pitch singing sopranos using dynamic three-dimensional magnetic resonance imaging.

Resonance-strategies with respect to vocal registers, i.e., frequency-ranges of uniform, demarcated voice quality, for the highest part of the female voice are still not completely understood.

The influence of gravity on respiratory kinematics during phonation measured by dynamic magnetic resonance imaging.

Respiratory kinematics are important for the regulation of voice production. Dynamic MRI is an excellent tool to study respiratory motion providing high-resolution cross-sectional images. Unfortunately, in clinical MRI systems images can only be acquired in a horizontal subject position, which does not take into account gravitational effects on the respiratory apparatus.

Sub-millisecond 2D MRI of the vocal fold oscillation using single-point imaging with rapid encoding.

Objective: The slow spatial encoding of MRI has precluded its application to rapid physiologic motion in the past. The purpose of this study is to introduce a new fast acquisition method and to demonstrate feasibility of encoding rapid two-dimensional motion of human vocal folds with sub-millisecond resolution.

Method: In our previous work, we achieved high temporal resolution by applying a rapidly switched phase encoding gradient along the direction of motion.

Effects of Nasalization on Vocal Tract Response Curve.

Background: Earlier studies have shown that nasalization affects the radiated spectrum by modifying the vocal tract transfer function in a complex manner.

Methods: Here we study this phenomenon by measuring sine-sweep response of 3-D models of the vowels /u, a, ᴂ, i/, derived from volumetric MR imaging, coupled by means of tubes of different lengths and diameters to a 3-D model of a nasal tract.

Results: The coupling introduced a dip into the vocal tract transfer function.

Respiratory kinematics and the regulation of subglottic pressure for phonation of pitch jumps - a dynamic MRI study.

The respiratory system is a central part of voice production as it contributes to the generation of subglottic pressure, which has an impact on voice parameters including fundamental frequency and sound pressure level. Both parameters need to be adjusted precisely during complex phonation tasks such as singing. In particular, the underlying functions of the diaphragm and rib cage in relation to the phonation of pitch jumps are not yet understood in detail.

Relevance of the Implementation of Teeth in Three-Dimensional Vocal Tract Models.

Purpose: Recently, efforts have been made to investigate the vocal tract using magnetic resonance imaging (MRI). Due to technical limitations, teeth were omitted in many previous studies on vocal tract acoustics. However, the knowledge of how teeth influence vocal tract acoustics might be important in order to estimate the necessity of implementing teeth in vocal tract models.

Regional ventilation during phonation in professional male and female singers.

The respiratory system is a central part of voice production, but details in breath control during phonation are not yet fully understood. This study therefore aims to investigate regional ventilation of the lungs during phonation. It was analyzed in 11 professional singers using electrical impedance tomography during breathing and phonation with maximum phonation time.

One-second MRI of a three-dimensional vocal tract to measure dynamic articulator modifications.

Purpose: To enable three-dimensional (3D) vocal tract imaging of dynamic singing or speech tasks at voxel sizes of 1.6 × 1.6 × 1.

Respiratory dynamics in phonation and breathing-A real-time MRI study.

The respiratory system is a central part of voice production, but for phonation neither the underlying functional relations between diaphragm (DPH) and rib cage (RC), nor differences to normal breathing are yet understood. This study aims to compare respiratory dynamics in phonation and breathing via dynamic MRI of the lung. Images of the breathing apparatus of 6 professional singers were captured in a 1.

The influence of water resistance therapy on vocal fold vibration: a high-speed digital imaging study.

Purpose: This study investigated the influence of tube phonation into water on vocal fold vibration.

Method: Eight participants were analyzed via high-speed digital imaging while phonating into a silicon tube with the free end submerged into water. Two test sequences were studied: (1) phonation pre, during, and post tube submerged 5 cm into water; and (2) phonation into tube submerged 5 cm, 10 cm, and 18 cm into water.

Morphometric Differences of Vocal Tract Articulators in Different Loudness Conditions in Singing.

Introduction: Dynamic MRI analysis of phonation has gathered interest in voice and speech physiology. However, there are limited data addressing the extent to which articulation is dependent on loudness.

Material And Methods: 12 professional singer subjects of different voice classifications were analysed concerning the vocal tract profiles recorded with dynamic real-time MRI with 25fps in different pitch and loudness conditions.

Ensuring safety and functionality of electroglottography measurements during dynamic pulmonary MRI.

Purpose: To combine vocal tract measurements with dynamic MRI of the lungs to provide fundamental insights into the lung physiology during singing.

Methods: To analyze vocal fold oscillatory patterns during dynamic lung MRI, an electroglottography (EGG) system was modified to allow for simultaneous EGG measurements during MR image acquisitions. A low-pass filter was introduced to suppress residual radiofrequency (RF) coupling into the EGG signal.

A Comparison of Different Methods to Generate Tooth Surface Models Without Applying Ionizing Radiation for Digital 3-Dimensional Image Fusion With Magnetic Resonance Imaging-Based Data of the Head and Neck Region.

Objective: The 3-dimensional display of the vocal tract and teeth is necessary in numerous clinical and scientific contexts. Due to the different tissue properties this can only be achieved by combining different imaging techniques. A comparison of methods to record the tooth surface to create combined models of the vocal tract and teeth without applying ionizing radiation is displayed in this study.

Articulation and vocal tract acoustics at soprano subject's high fundamental frequencies.

The role of the vocal tract for phonation at very high soprano fundamental frequencies (F0s) is not yet understood in detail. In this investigation, two experiments were carried out with a single professional high soprano subject. First, using two dimensional (2D) dynamic real-time magnetic resonance imaging (MRI) (24 fps) midsagittal and coronal vocal tract shapes were analyzed while the subject sang a scale from Bb5 (932 Hz) to G6 (1568 Hz).

Acceleration of MRI of the vocal tract provides additional insight into articulator modifications.

Purpose: To accelerate dynamic imaging of the vocal tract during articulation.

Materials And Methods: Five subjects were imaged by magnetic resonance imaging (MRI) while repeating the word "Partikel" at 90 beats per minute, using both a radio-frequency-spoiled radial gradient echo sequence with golden angle projection rotation and a previously applied real-time Cartesian sequence. The acquired data were reconstructed using a CG-SENSE method and Cartesian reconstruction.

Weight-bearing MR imaging as an option in the study of gravitational effects on the vocal tract of untrained subjects in singing phonation.

Magnetic Resonance Imaging (MRI) of subjects in a supine position can be used to evaluate the configuration of the vocal tract during phonation. However, studies of speech phonation have shown that gravity can affect vocal tract shape and bias measurements. This is one of the reasons that MRI studies of singing phonation have used professionally trained singers as subjects, because they are generally considered to be less affected by the supine body position and environmental distractions.