Different voice qualities result from distinct vocal fold modes

Evidence

The frequency spectrum of the regular pressure pulses generated by the vibrating vocal folds during speech and singing consists of all harmonics with an amplitude change on average of −12 dB per octave rise in frequency (see the illustration on the right in Figure 4.35). Thus for every doubling in frequency, equivalent to an increase of one octave, the amplitude reduces by 12 dB. The amplitudes of the first, second, fourth and eighth harmonics (which are separated by octaves) in the figure illustrate this effect. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1335 (#expands, via linked claim)

Categorization

• XREF: connects to: Vocal tract shape determines voice timbre far more than vocal cords do — Eric J. Heller, Why You Hear What You Hear- An…, 1633; A sinusoidal vocal fold wave would make speech impossible; A huge variety of speech sounds can be made without vocal folds (+5 more)

Broader Connections

• Vocal fold pulses produce harmonics falling 12 dB per octave #expands (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 1335
• A huge variety of speech sounds can be made without vocal folds #complicates (0.75)
• Throat singers create melodies by shaping vocal-tract resonances #qualifies (0.72)