Factor analysis (principal component analysis followed by varimax rotation) had shown that three common factors appear across 20 critical-band power fluctuations derived from spoken sentences of eight different languages/dialects [Ueda et al. (2010). Fechner Day 2010. Padua. https://www.roneverhart.com/A-Pea-in-the-Pod-Clip-Down-Nursing-Bra-Black-L/