Does subglottal resonance have a significant influence on register transition when singing falsetto
? To find out, investigators at the University of Iowa decided on an innovative approach – involving helium. Or, more accurately, Helox (a.k.a. Heliox
) a mixture of helium and oxygen [see safety note below].
Because helium is considerably less dense than normal air mixtures, the vocal resonant frequencies of those who breathe it tend to be higher – suggesting a possible application in falsetto research.
Reference: see this video of Lionel Ritchie singing ‘Hello’ (with helium).