A recent addition to the list of radio communication annoyances is an increasingly prevalent vocal mannerism, usually in younger pilots and controllers, where the speaker's voice trails into a low, gravely register. People who study voice and speech disorders have a name for this type of phonation: Vocal fry.
Vocal fry is a form of phonation, characterized by a distinct laryngeal vibratory pattern, distinct acoustic features, and a distinct vocal quality. Vocal fry has been referred to as pulse register, creaky voice, stiff voice, or glottal fry. ... in psycholinguistic research, the terms “glottalization” or “irregular phonation” are the preferred terms to describe this mode of phonation.It used to be that vocal fry was considered a clinical voice disorder, most often related to contact granuloma on the vocal cords. Then in 2011, researchers at the Department of Communication Sciences and Disorders at Long Island University published the results of their research: Habitual Use of Vocal Fry in Young Adult Female Speakers. 34 female college students, aged 18 - 25 years of age who were native speakers of Standard American English (SAE) were studied. The results showed that roughly two-thirds of the women habitually used vocal fry, that it was most likely to occur at the end of sentences, and that it appears the use of the vocal fry register may now be common in some adult SAE speakers. Before you cry foul and raise accusations of sexism, another study showed a similar, but a less common use of vocal fry in young males.
So what? Younger people think it's awesome to talk like Millhouse. What's the big deal? Well, aside from the use of vocal fry hurting your chances of getting a job during an interview, this type of vocalization does not carry very well over a two-way radio. Start with a bad radio, then add some static, a crowded radio frequency, and a pilot or controller with a tendency to mumble and you get a messy sort of verbal stew. Throw vocal fry into the mix and things only get worse.
Why younger people, especially young women, tend to use vocal fry is a topic of debate. One theory is that there may be a perception among these speakers that vocal fry makes them sound disaffected or relaxed. Another theory is that a low vocal register represents the speaker's lack of conviction in what they are saying, like ending every statements with a question inflection? Or could it be that the decimation of music programs in primary and secondary schools that started in the 1980's spawned a generation of young people who didn't learn to sing and missed out in learning how to use their breath in a way that would support their voice during speech.
I've trained several pilots recently (mostly male, by the way) who exhibited the habitual use of vocal fry while speaking on the radio, but not while talking directly to me in conversation. I pointed out to them that the controllers were constantly asking them to repeat their requests and that the reason was vocal fry just doesn't transmit very well. The best antidote to a tendency to use vocal fry on the radio is to become aware of the habit and then take the encouragement I offered one pilot:
"Use your high voice."