Vibrato

literature review

1. Perceptual Evaluation of Vibrato Models

Vincent Verfaille, Catherine Guastavino, Philippe Depalle

Proceedings of the Conference on Interdisciplinary Musicology (CIM05)

• spectral envelope modulation
• frequency-dependent hysteresis behavior
• test: preference for sounds with modulated spectral envelope
• offers great literature review & background info on vibrato pitch, rate, extent, shape, and temporal evolution
• provides equations for modeling FM, AM, SEM pulsations
• vibrato is made of at least one of these three kind of modulations:

1. amplitude modulation (predominant in wind and brass instr)
2. frequency modulation (predominant in voice and string instr)
3. spectral envelope modulation and hysteresis (existing in wind, brass, voice)

• Questions & thoughts:

* How much of the analysis is instrument-specific, and how much is it performer/ context/ style-specific?

* It'd be interesting to see a more music-passage specific (higher level) analysis as opposed to instrument-specific modelling

1. An Investigation of Vocal Vibrato for Synthesis

Robert Maher, James Beauchamp

• focuses on vocal vibrato & presents a new panned-wavetable synthesis method
• role of spectrum modulation
• findings: "Inclusion of typical random fluctuations of vibrato rate, vibrato depth, and nominal sung frequency resulted in no quality preference over examples with constant values. Inclusion of vibrato-induced spectrum modulation resulted in a substantial improvement over examples having constant spectra."