Among the 25 to 45 percent of the workforce in the United States who make use of their voices professionally are the air traffic controllers. Therefore, it is imperative for their listeners to understand what they are communicating. Teachers, air traffic controllers, and university lecturers have a high prevalence of voice disorders referred to as "dysphonia." Also, other professions that are at risk include clergy, attorneys, counselors, and performers.
For these professions, voice disorders are not only a problem. Indeed, 1 in 13 American adults reported a voice problem in the past year. Only a minority of them got treatment, further perpetuating the overall problem.
A team of researchers from Florida Atlantic University and Towson University conducted a study to determine if there are differences in speech intelligibility (the ability of a listener to recover a speaker's message) in healthy voices compared to those who have voice disorders including breathiness, hoarseness, loss of voice or a "croaky" voice.
Also, the researchers decided to know if using listener "strategies" like paying close attention to the words or using other words to try to figure out the message would increase speech intelligibility. Till present, no research has investigated if listener strategies improve intelligibility scores in speakers with voice disorders.
The first author of the study and an associate professor in the Department of Communication Sciences and Disorders in FAU's College of Education, Connie K. Porcaro said that a speaker's intelligibility is impacted not only by the abilities of the speaker but also by the listening environment and skills employed by the listener. Moreover, listeners receive less salient information to process when they are listening to a person with a voice disorder.
Published in the Journal of Voice, the results of the study reveal that overall, speakers with vice disorders demonstrated a tenfold increase in the number of speech intelligibility errors compared to speakers with healthy voices. Also, added to significant differences in the number of errors between healthy speakers and those with voice disorders, listeners also had significantly more overall errors on content words (listener transcribed "cat" for "dog") than articles (listener transcribed "the" for "a") with voice type.
Ultimately, the researchers explored the results of the voice quality ratings and discovered that speakers with a "breathiness" quality in voice ranging from moderate to severe had a higher number of speech intelligibility errors. Breathiness was the most predictive factor (41 percent) of the variance of speech intelligibility errors.
