Purdue University researchers found that how you get louder is a function of how you're told to speak louder and environmental cues.
Far more surprising, they discovered that trying to talk louder in response to verbal or other cues involves different sets of muscles and setting internal performance goals all accomplished subconsciously, involving neural control of the respiratory system.
"It's entirely shifted my thinking about how the respiratory system works in speech," lead researcher Jessica E. Huber said. "We never viewed respiration as a flexible system, just whether it was efficient or not. But we found that respiratory control is very context-dependent, and changes in the linguistic or cognitive load of the speech task alters the neural control of the respiratory system," Huber added.
The study, entitled "Changes to respiratory mechanisms during speech as a result of different cues to increase loudness," appears in the June issue of the Journal of Applied Physiology, published by the American Physiological Society. The research was conducted by Jessica E. Huber, Bharath Chandrasekaran and John J. Wolstencroft, Department of Speech, Language and Hearing Sciences, Purdue University.
Rethinking childhood speech therapy, helping adults with injuries or Parkinson's
The results have the potential to greatly influence speech therapy in cases ranging from spinal injury to Parkinson's disease, cerebral palsy, multiple sclerosis, stroke or other brain injury. The study said it is "important to consider the efficiency of the patterns elicited by these cues, from a work perspective, when planning a treatment."
"Since the respiratory system provides the pressure that allows us to