Finding the Ring: Comparing the Singer’s Formant and Singing Power Ratio in Carnatic Classical Singers

The perceptual “ring” or resonance is a defining feature of the singing voice, contributing to projection, tonal richness, and expressive quality. In Carnatic classical singing, cultivating this resonant tone is central to both artistry and vocal efficiency. This study examined the relationship between acoustic measures of resonance—the Singer’s Formant (Fs) and Singing Power Ratio (SPR)—and auditory-perceptual judgments following Resonant Voice Therapy (RVT). Twenty-nine trained Carnatic singers (18 females, 11 males) completed a 21-day RVT program based on Stemple’s hierarchical protocol. Pre- and post-training/a/-vowel singing (aalapana) samples were recorded and evaluated. Five expert speech-language pathologists, trained in voice science and Indian classical music, rated resonance using an 11-point equal-appearing interval scale. Long-term average spectrum (LTAS) analyses yielded Fs peak amplitudes and SPR values. Post-training samples demonstrated higher perceptual ratings and elevated Fs and SPR values. Fs and SPR were strongly correlated, while perceptual—acoustic associations were moderate, particularly among male singers. These findings suggest that resonant voice training enhances both perceptual and acoustic indicators of resonance, underscoring the role of targeted resonance training in improving spectral balance, projection, and overall vocal efficiency in professional voice users.