Effect of Historical Recordings on Vibrato

Welcome back to Voice Science Abridged. Today we are looking a study by Joshua D. Glasner and Aaron M. Johnson on the Effects of Historical Recording Technology on Vibrato in Modern-Day Opera Singers. This study was published in the July 2022 Journal of Voice.

According to various writings the rate and extent of vibrato has changed in opera singers over the last hundred and twenty years. However, the extent of the change may be effected by the historic audio recording technology. Glasner and Aaron set out to document this effect by recording twenty professional opera singers using modern recording technology and a Edison Home Phonograph using an accurately manufactured wax cylinder simultaneously. All twenty singers sang into the phonograph horn and microphone from 40 cm, singing messa di voce three times on the vowel /a/ at C4 for male singers and C5 for female sings.

Glasner and Johnson measured the vibrato rate, extent, jitter, and shimmer. In their analysis they found that the vibrato rate was consistent for both modern and historic recordings. There was a just noticeable difference in the vibrato extent, and an increase in jitter and shimmer on the wax cylinder recording. Because of this historic recording can be considered accurate if played at the correct rotating speed but extent, jitter, and shimmer are likely inaccurate.  This does confirm that vibrato rates have slowed over the past century.

If you have enjoyed this research summary please do check out the full paper in the Journal of Voice.

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