The Effect of Single Harmonic Tuning on Vocal Loudness

Abstract

The study addresses the benefit of tuning single harmonics with vocal tract resonances to increase vocal loudness. The loudness of theoretically constructed vocal sounds with variable levels of sound energy in the first, second, and third harmonics is computed on the basis of ISO standard 226:2003. In comparison to increased loudness with changes in overall spectral slope, it is shown that single harmonic tuning requires a greater range of SPL to produce a similar range of loudness. For example, a 10−40 dB increase in the level of a single harmonic produces less than two doublings of loudness, whereas a spectral slope change from 12 dB/octave to 3 dB/octave can produce a similar doubling of loudness with only a 5 dB SPL increase.

Tonality over a broad frequency range is linked to vocal learning in birds

“…All mechanisms to increase tonality (dynamic filtering; increased open quotient; closed-beak vocalization) seem to be associated with increased sound amplitude. Furthermore, the loudness of the emitted sound may depend in complex, interactive ways on relationships between the filter characteristics and the generated sound pressure levels [70], thus influencing how efficiently the generated sound is radiated at the mouth. Although data are available only for a few species (e.g.…”