Taking Apart the Mystery of Vocal Fatigue

Highlights

• Hamzeh Ghasemzadeh, assistant professor in UCF's College of Health Professions and Sciences, is tackling mysteries in communication disorders, starting with vocal fatigue.

• Childhood curiosity about taking things apart now drives his NIH-funded voice research.

• Using AI and wearable sensors, he's developing tailored strategies to protect and strengthen voices.

To better understand Assistant Professor Hamzeh Ghasemzadeh and his work, he goes back to a childhood memory of broken toys. Within hours of receiving little robotic figures or remote-control cars, he'd dissembled what had once been a carefully crafted package of technology. To him, sitting among the remnants of a new gift meant he was sitting in a circle of fun.

"My favorite game was to take the toys apart to see how they work and then try to put them back together," Ghasemzadeh says. "My parents saw my curiosity as a great thing."

"This is why I came to UCF. I've been able to jump right in and address mysteries that haven't received much attention."

That same curiosity now drives his research at UCF's School of Communication Sciences and Disorders, where he seeks to take apart discomforted voices, figuratively, so he can develop strategies to make each one whole again. Ghasemzadeh, who joined UCF in late Summer 2025 and will teach in the school's newly launched communication sciences and disorders doctoral program, has already secured one research project funded by the U.S. National Institutes of Health and is developing another.

"This is why I came to UCF," he says. "I've been able to jump right in and address mysteries that haven't received much attention until now."

A Common Problem Without Clear Answers

The first such mystery sounds quite straightforward: vocal fatigue, a common vocal complaint. Beneath the surface, however, it's deceptive. Solutions have mostly evaded scientists, leaving vocal fatigue as an ongoing problem for many people who rely on their voices, like coaches, public speakers, singers and teachers. Many of Ghasemzadeh's colleagues experience the very throat discomfort that he's deconstructing during the funded project just underway.

"We want to collect … multi-modal data and use machine learning models to analyze [vocal fatigue] and develop recommendations for each person."

"Some instructors get vocal fatigue quickly, some get it slowly and some don't get it at all," he says. "There's a genetic component, but there are also behavioral components. How do they use their voice? How often do they use it? What about the environment where they're using it? What about personality? We want to collect such comprehensive multi-modal data and use machine learning models to analyze it and develop recommendations for each person."

The recommendations might include pacing voice usage, projecting the voice efficiently and allowing the voice to recover. Ghasemzadeh envisions this model being predictive and - this is the part he stresses most - personalized.

"The approach to general medicine started with an assumption that while we're different on the outside, we are very similar inside. Patients with similar ailments took the same medications and [the] same dosages. But we now know that people don't always respond to pills the same way. If we can quantify how we're different inside, we can create a computational model to predict responses to medications and optimize treatment plans."

To integrate artificial intelligence (AI) into vocal fatigue solutions, subjects in Ghasemzadeh's study will wear sensors that track how and where they use their voices. He'll prompt them to perform specific vocal tasks and monitor their phonatory function throughout the day. The AI model will analyze these patterns in real time to identify early signs of vocal strain and predict when fatigue is likely to occur.

"We are different. Every prescribed solution should be different, too."

Participants will also visit his lab at the Communication Technologies Research Center in Central Florida Research Park, where specialists will collect imaging, aerodynamic and acoustic data. The highly equipped facility brings together America's leading hearing and voice scientists to develop new technologies and clinical tools for people with hearing loss or voice disorders.

With all of that in hand, including the technology, Ghasemzadeh and his team hope to unwind the mystery of vocal fatigue - one person at a time.

"That's the idea I want to put forward with every project," he says. "We are different. Every prescribed solution should be different, too."

From Engineering to Human Connection

Many would think a toy-reassembling boy is destined to become an engineer. That's what Ghasemzadeh thought, too. He earned bachelor's and master's degrees in electrical engineering and began his career with a focus on telecommunications and signal processing.

"There was something important missing," he says. "Human connection."

"Speech became my research interest because … it sets us apart as a species and as individuals."

He crossed paths with a close friend who mentioned his own research in a field Ghasemzadeh was vaguely familiar with: communication sciences and disorders. The conversation sparked Ghasemzadeh's enthusiasm for applying his expertise in areas such as signal processing to personally help others.

"Speech became my research interest because it's the signal we predominantly use to communicate," he says. "It sets us apart as a species and as individuals."

For example, it's quite easy to identify Ghasemzadeh without even seeing him. He sounds young yet intelligent enough to have dual doctoral degrees. There's an inflection of humility in his voice. The curiosity is always there, too. In fact, his peers have noticed, from his work, what his parents noticed among his broken toys: his curiosity leading to great things. Shortly after arriving at UCF, the American Speech-Language-Hearing Association chose Ghasemzadeh for its Early Career Contributions in Research Award.

"It's also a reminder that I'm early in my career," he says, "and the sky is the limit."

At the center of his work as a principal investigator is a belief that progress doesn't happen alone, but through teamwork.

"You have to surround yourself with different skillsets, all of us willing to take things apart that have never been taken apart, with everyone focused on one goal," Ghasemzadeh says. "When you win, I win and everyone wins."

Research reported in this publication was supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under award number R00DC021235. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

More Topics