Recent studies have demonstrated that human vocalizations above 1000 Hz can be realized within laryngeal mechanism M2. Here, subgroup M2d has been described as restriction of the vibrating vocal fold portion. Furthermore, there are hypotheses for ultra-high fundamental frequencies using epithelial-dominated oscillation. The presented data from high-speed video material of three subjects support these findings, showing oscillation at small anterior orifices of the vocal folds. The fundamental frequencies of audio recording, electroglottography, and glottal area waveform correspond. In one sample above 3 kHz, complex frequency combinations occurred, which were detectable in both the vocal fold oscillation and the acoustic spectrum.
Wingerath et al. (2026) studied this question.