The effect of resonance tubes on facial and laryngeal vibration – A case study

Vocal tract shape and acoustic adjustments of children during phonation into narrow flow-resistant tubes

“…Due to the non-linear coupling between the source and the filter (Titze, 2008;Titze et al, 2008) theoretical investigations have posited the role of an increase in the inertance as the main regulatory factor responsible for the therapeutic benefit of the flow-resistant tube exercises. Increase in the inertance with flow-resistant tube exercises (Titze, 2006) can be achieved as a result of either the lengthening of the anterior vocal tract (Story et al, 2000), the narrowing or semiocclusion of the lips for bilabial fricative /b:/ (Story et al, 2000), the narrowing of the epilaryngeal tube (Titze, 2001(Titze, , 2006Titze and Story, 1997), or the enhancement of low frequency inertance through vibration of the vocal tract walls (Fric and Hruska, 2017;Horacek et al, 2017). Vocal tract lengthening and semiocclusion at the lips increases the inertance primarily by driving vocal tract resonances to lower frequencies (Horacek et al, 2017;Story et al, 2000), whereas narrowing of the epilaryngeal tube and enhancing vibrations of the vocal tract walls increases the inertance without substantially altering the vocal tract resonances (Titze, 2006;Titze and Story, 1997).…”