RESUMO
OBJECTIVES: The present study aimed to assess the aerodynamic characteristics of vocally healthy metal singers when producing growl voice or reinforced falsetto. METHODS: Fifty-four participants (metal singers) were initially enrolled in this study, with 23 meeting the inclusion criteria. Sixteen participants performed growl voice and seven performed reinforced falsetto as a voice resource during metal singing. All participants were asked to undergo rigid laryngeal videostroboscopy to confirm the absence of laryngeal pathology. Then, subjects were aerodynamically assessed while performing growl voice or reinforced falsetto. RESULTS: Higher glottal airflow rate, sound pressure level, and subglottic pressure (Psub) for growl voice samples compared to vowel production without growl voice (keeping the same fundamental frequency [F0]) were found. Higher Psub, sound pressure level, and glottal resistance for high-pitched reinforced falsetto compared to naïve falsetto (keeping the same F0) were found. No differences for F0 were found for neither growl voice nor reinforced falsetto. CONCLUSIONS: It seems that growl voice is produced by decreasing vocal folds adduction and increasing Psub, which in turn, promotes an increased airflow rate. Reinforced falsetto is characterized by an increased vocal fold adduction and an increased Psub. A proper resonance strategy in reinforced falsetto and a decreased glottal adduction in growl voice might probably be the factors that contribute to prevent voice problems in singers who use these vocal resources, classically labeled as vocal abuse.
