By Dave DeFusco

For generations, people with hoarse voices have heard the same advice: don’t whisper. Whether recovering from a cold, vocal strain or a voice disorder, patients are often told that whispering can damage the vocal cords and make recovery more difficult. But what if that widely accepted recommendation is not fully supported by scientific evidence? 

That question inspired Nicole Aziz, a student in the Katz School’s M.S. in Speech-Language Pathology program, to investigate one of voice therapy’s most enduring beliefs. Presented at the 2026 Science, Technology and Health Symposium, her research project, “Hush is Harm? Debunking Whispering Myths in Voice Therapy,” examined existing scientific studies to determine whether whispering truly causes more strain or harm to the voice than normal speech. Her work also explored why the warning against whispering remains so common in clinical practice despite limited evidence. 

“Many patients are routinely advised to avoid whispering when they experience vocal fatigue or are recovering from a voice disorder,” said Aziz. “I wanted to look closely at the research and determine whether the evidence actually supports that recommendation or whether it has become a clinical myth that continues to be repeated without strong scientific backing.” 

To understand the debate, it helps to know how the voice works. When people speak normally, their vocal folds, often called vocal cords, come together and vibrate as air passes through them. These vibrations create sound and allow people to produce speech with pitch and tone. 

Whispering works differently. The vocal folds remain partially open and do not vibrate. Instead, air moves through a small opening, creating a soft, breathy sound through turbulence rather than vibration. Because whispering relies on increased airflow and a different configuration of the vocal folds, some clinicians have assumed it may place additional stress on the voice. Aziz, however, found that scientific studies have produced mixed results. 

“Research shows that whispering and normal speech use different physiological mechanisms, but that does not automatically mean whispering is more harmful,” she said. “The available evidence is inconsistent, and there is currently no clear consensus that whispering causes greater strain than speaking in all situations.” 

As part of her project, Aziz reviewed research describing the physical characteristics of whispered speech and compared those findings with common beliefs encountered in clinical training and practice. She identified several longstanding assumptions about whispering and evaluated whether they were supported by empirical evidence. 

Her review found that while whispering can be less efficient than normal speech because it requires greater airflow, studies have not consistently demonstrated that it causes more damage to the vocal mechanism. In some circumstances, certain forms of whispering may even be less demanding than speaking loudly or forcefully. 

The findings highlight the importance of evidence-based practice, a cornerstone of modern healthcare, which encourages clinicians to make recommendations based on the best available research rather than tradition alone. Aziz said this approach is especially important when educating patients.

“When patients receive advice, they deserve to know that it is grounded in current scientific evidence,” she said. “If the evidence is unclear, clinicians should recognize that uncertainty and tailor recommendations to the individual rather than relying solely on long-held assumptions.” 

Andrew Christler, Aziz’s advisor and a clinical assistant professor in the Katz School’s medical speech-language pathology program, said the project demonstrates why critical examination of established practices is essential in healthcare. 

“Voice therapy has evolved significantly over time, but some recommendations continue to be passed down from one generation of clinicians to the next without being rigorously reexamined,” said Christler. “Nicole’s work encourages practitioners to revisit the evidence and ensure that patient care reflects what research actually tells us rather than what has simply been accepted for years.”