Objective: This study investigated whether there are differences between shouting and belting, that has been described as ‘yell-like’ singing.
Methods: Aerodynamic, electroglottographic (EGG), and acoustic signals were recorded from 8 trained CCM singers with expertise in belting and from 8 vocally untrained participants (4 males and females in both groups) during loud syllable repetitions of /pe/ on three pitches (males: C#4, D#,4, F4 and females: F4, G4, A4). To produce overlap between SPL ranges of the compared groups two loudness levels were recorded (moderate and very loud). The signals were analyzed for an estimate of subglottal pressure (Psub), mean airflow, glottal resistance (Psub/flow), contact quotient (CQ), maxima of the first derivative of the amplitude normalized EGG (MDEGG), SPL, loudness, singing power ratio (SPR), and level difference between the first harmonics (H1-H2). From the aerodynamic and EGG variables, subglottal power (PWsub, i.e. mean Psub * mean airflow), and several estimates of vocal efficiency and economy were calculated.
Results: Neither SPL nor loudness or any spectral measures differed significantly between belting and shouting. CQ in males (p<0.05) and MDEGG in females (p<0.05) were slightly higher in belting. Mean airflow was substantially lower in males (p<0.001), and Psub in females (p<0.001) in belting. Consequently, PWsub was lower in both males (p<0.001) and females (p<0.05). Vocal efficiency (acoustic power or loudness divided by PWsub) was higher in belting (From acoustic power: males p<0.001 and females p<0.001. From loudness: males p<0.001 and females p<0.01).
Conclusions: In the studied sample, the aerodynamic variables best distinguished trained belting from untrained shouting. The observed differences may reflect enhanced vocal economy in belters due to training.