Acoustic studies of the voice source in male singers

This paper reviews various recent investigations with various co‐workers of male singers' vocal fold function mainly studied by inverse filtering for deriving the waveform of the transglottal airflow during phonation. Theoretical and experimental studies confirmed the dominating acoustic importance of (1) the peak airflow Û_g for the amplitude of the voice source fundamental, and (2) the negative peak amplitude of the differentiated waveform dU/dt for the SPL of the radiated sound. Unlike nonsingers, some professional baritone and bass singers have been found to retain a high Û_g during loud tones at high pitches. Different strategies are possible for increasing dU_g/dt for loudness variation: increasing U_g, increasing the duration of the closed phase, and skewing the pulse shape. Different singers use different combinations of these alternatives depending on pitch, loudness range, and voice type. Some of the physiological correlates of these strategies can be postulated. Here, Û_g seems highly dependent on the degree of glottal adduction and dU_g/dt on subglottal pressure. However, influence of the breathing strategy has also been quantitatively demonstrated.