Axe ’Em, Jacks!
Where Voice Meets Medicine, Science and Art
The Vocal Arts and Science: Evaluation and Enhancement, or VASEE, clinic and lab was proudly established through the generous support of the STARs grants from the University of Texas System. We are deeply grateful for this invaluable contribution to advancing our mission in voice research and clinical excellence. The VASEE clinic and lab is under the direction of Dr. Nandhu Radhakrishnan.
About the Director - Dr. Nandhu Radhakrishnan
Dr. Nandhu Radhakrishnan was born and brought up in India and moved to the US for his doctoral studies. He received his doctorate at Bowling Green State University, Ohio and completed his clinical fellowship at the University of Pittsburgh Voice Center, Pennsylvania. Currently, he is a professor in the Communication Science and Disorders Program at Stephen F. Austin State University.
His areas of specialty include clinical, professional, and performance voice issues. He has published several manuscripts and conducted national and international workshops related to the assessment and intervention of voice. He has designed innovative voice therapy approaches called the Nasal Resistance (NR) technique and the Voiced Whistle technique. He is a member of the Editorial Board of the Journal of Voice, Voice Science Advisory Committee of the National Association of Singing, Former Central Governor of the Pan American Vocology Association, Voice Foundation, and Voice and Speech Trainers Association.
Apart from his profession, Dr. Nandhu is a playwright in Tamil, his native language, stage artist, videographer, hobby chef and YouTuber. He is fluent in English, Tamil and Hindi.
Human Voice for Communication
The human voice is a fundamental tool for communication, allowing us to express emotions, share ideas and convey messages. It is the cornerstone of spoken language, creating connections between individuals and fostering social bonds.
Importance of Voice
Our voice is not just a means of communication; it plays a critical role in personal identity, profession and social interactions. For singers, actors, teachers and public speakers, the voice is a vital asset. Maintaining a healthy voice is essential for overall well-being and professional success.
Factors Affecting Vocal Health
Several factors can impact vocal health, such as:
- Environmental: Exposure to pollutants, allergens or dry air.
- Behavioral: Overuse, misuse or chronic throat clearing.
- Lifestyle: Smoking, drinking, dehydration and diet.
- Medical: Conditions like acid reflux, respiratory infections or neurological disorders.
Voice Disorders and Classification
Voice disorders can affect pitch, loudness and vocal quality. They can be classified into three main categories:
- Organic Voice Disorders: Structural abnormalities of the vocal folds, such as scars, sulcus vocalis, etc.
- Functional Voice Disorders: Caused by improper use or overuse of the voice with or without any structural abnormality (e.g., vocal nodules, polyps, muscle tension dysphonia).
- Neurogenic Voice Disorders: Resulting from nerve damage or degeneration, such as vocal fold paralysis, spasmodic dysphonia, hypophonia due to Parkinson’s disease, etc.
Assessment of Voice
Voice assessments can be both subjective and objective, helping to evaluate vocal function and diagnose disorders.
Subjective Assessment
- Perceptual Voice Evaluation: Trained listeners rate vocal quality on parameters such as pitch, loudness, quality, and effort.
- Patient Self-Assessment: Tools like the Voice Handicap Index, or VHI, allow patients to describe their perceived vocal difficulties.
Objective Assessment
Objective evaluations use instrumentation to assess various aspects of voice production:
Acoustic Evaluation
Analyzes sound produced by the vocal folds.
- Instrumentation: The use of acoustic software has been the primary approach to analyze parameters related to vocal fold vibration and vocal tract resonance.
- Key Measures: Fundamental frequency (pitch), intensity (loudness), jitter, shimmer, harmonics-to-noise ratio, Cepstral peak Prominence, etc.
Aerodynamic Evaluation
Examines the airflow and pressure during voice production.
- Instrumentation: From a low-cost stopwatch and spirometer, to Pneumotachograph that measures pressure and airflow.
- Key Measures: Maximum phonation time, Subglottal pressure, phonation threshold pressure and airflow rate.
Electroglottographic Evaluation
Measures the electrical impedance between two electrodes placed on the neck to assess vocal fold contact.
- Instrumentation: Electroglottograph, or EGG.
- Key Measures: Closed Quotient, or CQ, which reflects the percentage of time the vocal folds are in contact during the glottal cycle.
Stroboscopic Evaluation
Visualizes vocal fold vibrations by using a strobe light synchronized with vocal fold motion.
- Instrumentation: Videolaryngostroboscope.
- Key Measures: Visualization of pathology, Vocal fold symmetry, amplitude and mucosal wave propagation.
Current Research at VASEE
At VASEE, we are dedicated to advancing the science of voice. Our current projects focus on:
- The effect of the Nasal Resistance, or NR, technique on improving vocal quality and glottal adduction.
- Perceptual and objective analysis of performance voice.
- The role of vocal training in enhancing vocal health for professional voice users, such as teachers and singers.
- Exploring voice disorders related to Parkinson’s disease, aging and vocal fold paralysis.