“…Studies have already characterized formants or tract resonances for different singing styles (classical, belting, see Stone et al, 2003;Sundberg et al, 1993), or different qualities or techniques (twang, "forward," "throaty," "resonant," or "open" singing; see Bloothooft and Pomp, 1986a;Hertegard et al, 1990;Steinhauer et al, 1992;Ekholm et al, 1998;Titze, 2001;Vurma and Ross, 2002;Titze et al, 2003;Bjorkner, 2006;Garnier 2007b).…”