The purpose of this study was to investigate the laryngeal behavior involved during vocal production of highest pitched notes of the human vocal ranges in Flute in M3 Register, in Whistle Register and in a newly formulated by us Hiss Register, depending on the Laryngeal Vibratory Mechanism M3. Observations were carried with Stroboscopy and High Speed Digital Imaging and with spectrographic and psycho-acoustic analysis by means of a software system having a wide spectral range (0-20.000 Hz). Results indicate that at the highest pitch vocal folds vibration is significantly reduced (glottic contact is incomplete, with intraharmonic noise and overtones within 10 to 18 kHz range) or absent (glottic contact is complete and no intra-harmonic noise).
Keywords: laryngeal vibratory mechanism M3, HSDI, acoustics, male and female vocal range, flute-in-M3 register, whistle register, hiss register.