Figure 3: Comparison between phonation of/a/and/E/on EGG (contact quotient) in all semi-occluded vocal tract exercises (a) Comparison between humming/a/vs. all four with/e/(b) Comparison between HOM/a/vs. all four with/e/(c) Comparison between tongue trill/a/vs. all four with/e/(d) Comparison between lip trill/a/vs. all four with/e/