Analysis of high-frequency energy in singing and speech

Abstract

The human singing and speech spectrum includes energy above 5 kHz, but this portion of the spectrum is typically ignored in speech and voice science. Generally it has been assumed that this high-frequency energy (HFE) contributes to only qualitative percepts of singing and speech, but prior work shows HFE contributes to several non-qualitative percepts, including speech intelligibility. To begin an in-depth exploration of HFE, a database of multi-channel anechoic high-fidelity recordings of singers and talkers was created and analyzed. Third-octave band analysis from the long-term average spectra (LTAS) showed that production level (soft vs. normal vs. loud), production mode (singing vs. speech), and phoneme (for voiceless fricatives) all significantly affected HFE characteristics. Female HFE levels were significantly greater than male levels only above 11 kHz. As expected, HFE was found to be highly directional toward the front of the singer/talker. While this information resulted from a study initially focused on singing voice aesthetic, it is pertinent to various areas of acoustics, including vocal tract modeling, voice synthesis, augmentative hearing technology (hearing aids and cochlear implants), cell phone technology, and training/therapy for singing and speech. [Work supported by NIH-NIDCD.]