According to The Brighter Side of News, researchers Haruka Kondo, Sotaro Kondoh and Shinya Fujii at Keio University staged a simulated classical vocal competition in a 720-seat concert hall, published in the Journal of Voice.

Twenty-two Japanese classical singers — 10 men and 12 women — each sang "Caro mio ben" in E-flat major, unaccompanied, after a 10-minute warm-up and in a single take.

Five professional singers who also teach voice scored each performance out of 100 and rated six attributes on seven-point scales: vibrato, resonance, timbre, diction, intonation and expressiveness.

The consensus-breaking finding, as The Brighter Side of News reports it, is that a ringing voice can impress a judge without being the loudest voice onstage.

Three attributes showed clear positive associations with overall scores — vibrato, resonance and expressiveness — while timbre, diction and intonation showed no statistically significant independent associations.

Even more striking, recorded loudness showed no significant link to scores at all, though the publication notes the microphone sat about 20 centimeters from each singer's mouth while judges sat much farther away.

The single most telling acoustic measure was the singing power ratio: greater prominence in the 2–4 kilohertz band, overlapping the singer's formant region that helps trained voices carry without amplification, was associated with higher scores.

Vibrato produced the study's most complicated pattern.

The Brighter Side of News reports that faster vibrato was associated with lower scores among male singers, while wider vibrato was associated with higher scores among female singers — and the experiment could not determine whether the differences reflected anatomy, voice type, aesthetic expectations or vocal control.

The researchers also measured how quickly vibrato oscillated and how wide its range was, analyzing only vowel segments where pitch fluctuations were detectable and sufficiently regular.

Overall, the acoustic model explained about 33% of score variation, rising to about 40% when judge-level differences were included — leaving most of the expert ear beyond measurement.

Kondo, an operatic soprano who has competed herself, told The Brighter Side of News the study "bridges the gap between artistic intuition and science and does not aim to replace the expert ear."

The proposed applications include teaching feedback that pairs listening with measurements, clearer competition scoring sheets, and AI voice tools reflecting expert evaluation — none of which the study built or validated.

Real-world technique still runs on practice rather than metrics: 96.3 KKLZ reports that Heart's Ann Wilson, with over five decades of performing behind her, warms up for an hour before every show simply by singing along to a favorite album, currently Elton John, because his "lots of words, lots of big jumps and skips and incredible pitch" make the challenge itself the warm-up.