National Center for Voice and Speech

09/04/2026

Just breathe.

09/03/2026

With ICVPB about a month away, we decided to highlight some of our presenters. First up, Keynote Speaker Nicole Li-Jessen. She will kick off the conference on Wednesday morning, October 7. We look forward to hearing from Dr. Li-Jessen. Here is her bio:

Dr. Nicole Y. K. Li-Jessen is a Professor at McGill University and Canada Research Chair in Personalized Medicine of Upper Airway Health and Diseases. A speech pathologist and computational biologist by training, she earned her clinical degree at the University of Hong Kong, her PhD in computational biology at the University of Pittsburgh under Prof. Katherine Verdolini-Abbott, and completed postdoctoral training in tissue engineering with Prof. Susan Thibeault at the University of Wisconsin–Madison. She leads McGill’s Voice and Upper Airway Research Laboratory, the only research group combining high-fidelity biocomputing with vocal fold bioengineering, and has trained more than 50 researchers across engineering, computing, and clinical sciences. Her program advances Digital Health Twins — dynamic, patient-specific virtual replicas of vocal fold systems that predict disease progression and guide regenerative therapies — across four integrated themes: computational medicine, tissue engineering, digital wearables, and health stigmatization. She has published 57 peer-reviewed articles and 7 book chapters, serves as Section Editor for PLOS Digital Health and on the editorial board of Scientific Reports, and received McGill’s Principal’s Prize for Excellence in Teaching in 2018.

09/02/2026

"While all speakers modulate their voice quality, some speakers do so more easily than others. Previous studies suggest that the ability to modulate voice quality depends on the ability to control vocal fold medial surface vertical thickness, among other factors. While it is well known that vocal fold vertical thickness can be increased by an inferior medial bulging of the vocal folds due to actions of the thyroarytenoid (TA) muscle, the underlying mechanism of how TA muscle activation produces inferior medial bulging remains unclear. In this computational study, we show that the TA muscle fiber orientation had a large effect on the extent of inferior medial bulging and vertical thickness increase under TA muscle contraction in a three-dimensional model of laryngeal muscle activation based on high-resolution magnetic resonance imaging. Maximum inferior medial bulging and thickness increase occurred when the TA muscle fiber orientation angle ranged between 22–32° relative to the anterior-posterior direction. At these optimal fiber angles, TA muscle activation was able to induce a horizontal rotation of the arytenoid cartilage, which medialized the vocal process and the inferior portion of the medial surface more than the superior portion of the medial surface, thus increasing vertical thickness. In contrast, the lateral cricoarytenoid muscle induced a rocking rotation of the arytenoid cartilage, which medialized the superior medial surface slightly more than the inferior medial surface, and thus had an opposite and much-reduced effect on vocal fold thickness. It is hypothesized that potential individual differences in TA muscle fiber orientation may contribute to individual differences in the ability to modulate voice quality."

The abstract for "Thyroarytenoid muscle fiber orientation regulates the ability to modulate vocal fold vertical thickness" by Tsukasa Yoshinaga and Zhaoyan Zhang. First published in PLOS One, December 4, 2025. Featured this week in NCVS Notes.

09/01/2026

Available now.

Vocology: The Science and Practice of Voice Habilitation is the first major textbook written in the field of Vocology. It addresses the fundamental postulates and exercises underlying voice habilitation, the art and science of taking a voice beyond normal conversational skills. It introduces voice m...

08/31/2026

"Consider the hand-clap as an example. Prior to contact between the hands, air is displaced (moved) between the hands in relatively large quantities. For a 10 cm x 10 cm hand surface and a 30 cm maximum separation between the hands, 3,000 cm³ (3 liters) of air are displaced. If this occurs in the time period of about a second (usually less than that in a repeated hand-clap), more airflow is produced than in any normal speech utterance. Yet no sound is perceived until the hands collide. At contact the flow of air between the hands (in several directions) is suddenly interrupted, giving rise to intense audible sounds. Although sound is indeed produced while the hands are moving together and apart, the frequency is too low to be heard.

Another example of the importance of flow interruption in generating audible sound is the siren. Here a jet of air is aimed at holes that are equally spaced around the perimeter of a rotating wheel. As the wheel turns, the jet of air is alternately passed by the holes or blocked by the space between the holes. This periodic interruption of airflow is a very efficient way of producing high intensity sounds.

Flow-induced vibration of the vocal folds is essentially a combination of the sound-producing mechanisms of the hand-clap and the siren. Sudden closure of the glottis interrupts the flow of air, creating a large (negative) pressure disturbance in the vocal tract just above the vocal folds. This pressure disturbance, when propagated along the vocal tract and reflected at various places, becomes the modified (filtered) sound that we hear."

from "Conserving Airflow in Singing" by Dr. Ingo Titze. First published in NATS Bulletin, a predecessor to the Journal of Singing. Sept/Oct 1986

08/28/2026

I guess they made a lot of noise.

08/27/2026

ICVPB is fast approaching! Be sure to get your conference passes now!

Join us for ICVPB 2026 in Salt Lake City, Utah. This conference brings together top voice scientists to discuss voice physiology and biomechanics.

08/26/2026

"Parkinson’s disease (PD) is widely known for its impact on movement: tremor, rigidity, and slowed gait. Less visible, but equally disabling, are the changes it imposes on the voice (Duffy, 2020). Most people with PD (PwPD) develop hypokinetic dysarthria, the first symptom of which is usually reduced vocal intensity (a hallmark of hypophonia), along with a diminished pitch range and reduced articulatory precision (Duffy, 2020). These changes compromise communication quality and, consequently, social participation and quality of life (Kavya et al., 2022).

Voice production is a complex process that is both motor and non-motor, which is key to understanding the voice deficit in PwPD, who present symptoms of both types (Poewe et al., 2017). This complexity represents both a clinical and a scientific challenge. Many PwPD do not perceive changes in their own voice, such as a reduction in loudness; they may fail to notice this change, or believe their voice is adequate, even when those close to them repeat phrases such as “I can’t understand you” or “speak louder” (Silbergleit et al., 2021; Contreras-Ruston et al., 2024). This mismatch manifests in two distinct ways, how PwPD perceive their own voice in real time while speaking, and how they describe their own voice when asked about it without having spoken, or even after speaking. Both patterns reflect a deeper alteration, a failure in the sensory feedback systems that normally allow speakers to control and adjust their voice in real time (Hammer & Barlow, 2010), as well as in how that system updates information about one’s own voice after speaking, a process related to voice awareness."

from the introduction to "Is It Self-Awareness or Is It Sensory Feedback? Difficulties in Self-Perception of One’s Own Voice in People with Parkinson’s Disease." by Francisco Contreras-Ruston. First published in NCVS Insights, 26 August 2026

08/25/2026

Available now.

Read one of the latest publications on SOVT by Ingo Titze and Karin Titze Cox.

08/24/2026

"Airflow is required for every sound that is generated in speech and song. Since the supply of air from the lungs is limited by the vital capacity, most people have experienced the need to conserve air during prolonged phonation. The question is, how does one conserve air without seriously reducing vocal (acoustic) power?

Let's briefly review how much air we have to work with. A typical vital capacity for humans is about one gallon (approximately four liters) of air. Only a small fraction of this (about 10% to 20%) is used in a quiet breathing cycle. Likewise, in conversational speech, where the length of a phrase is not dictated, only a small portion of the vital capacity is used. During strenuous activity, however, which may include singing and shouting, most of the vital capacity may be drawn upon.

The raw aerodynamic power available from the lungs for sound production is the product of lung pressure and mean (average) flow. Thus, all else being equal, more airflow provides more raw aerodynamic power for speech. But the acoustic output power, which is always a fraction of the available aerodynamic power, depends as much on the abruptness with which the flow is changed as on the amount of flow itself. In particular, the high-frequency content of the sound, to which our ears are most sensitive, is very much dependent upon the suddenness with which the air disturbance is created."

from "Conserving Airflow in Singing" by Dr. Ingo Titze. First published in NATS Bulletin, a predecessor to the Journal of Singing. September/October 1986