Hi-Fi voice: observations on the distribution of energy in the singing voice spectrum above 5 kHz

Current audio technology enables the weak spectrum of the voice above 4‐5 kHz to be studied reliably. It is known that energy in the 5‐20 kHz range can be perceived even when it is 50 dB or more below the main voice spectrum peak. Also, these upper frequencies are conventionally emphasized in the production of popular vocal music; yet very few studies of the acoustic content of this range have been made. High fidelity recordings were made of singers sustaining vowels at varying levels of vocal effort. A general characterization of the two highest octaves (5‐20 kHz) was sought. The prevalence of high‐frequency energy, the variation of harmonics to noise over frequency, and the covariation with overall SPL were all highly variable, but several landmark features were identified. In addition to the commonly observed zero at 4‐5 kHz, zeroes were often seen also around 6 and 12 kHz, as were clusters of resonances in the regions 7‐10 kHz and 13‐16 kHz. Harmonic energy was observed to over 16 kHz in strong female...