It tends to happen when the speaker tries to deepen his or her voice and just ends up squeezing their vocal cords instead, almost driving them into a monotone.
Researchers from Duke University and the University of Miami decided to test how the phenomenon affects the way job candidates are perceived by potential employers, so they recorded 14 men and women between the ages of 19 and 30 speaking in both a natural tone of voice and vocal fry. They then had 400 men and 400 women listen to the recordings and evaluate the speakers. The evaluators were asked to choose which voice was more educated, competent, trustworthy, and attractive, as well as which one they would hire.
More than 80% of the time, evaluators chose the natural voices as the winners across all five judgments. It’s a warning that hiring managers are probably making the same subconscious judgments during interviews.
Strikingly, women’s voices with vocal fry tended to be judged more harshly than men.
"One possible reason for this is that a lowered register is seen as more atypical for women than men," said Duke professor Bill Mayew. "What was even more interesting is that female listeners perceive vocal fry more negatively than male listeners."
The greatest area of impact for vocal fry was on trustworthiness – meaning that women with creaky voices during an interview may actually be more trustworthy that you perceive.
If you’ve ever heard somebody speak with a creaky voice, you know what ‘vocal fry’ sounds like. Formally known as glottalization, it’s a speech disorder that’s becoming an increasingly acceptable way to talk, thanks to personalities like Ira Glass, Zooey Deschanel and Britney Spears.