Flow ball-assisted voice training: Immediate effects on vocal fold contacting

Abstract

ObjectiveEffects of exercises using a tool that promotes a semi-occluded artificially elongated vocal tract with real-time visual feedback of airflow – the flow ball – were tested using voice maps of EGG time-domain metrics. MethodsTen classically trained singers (5 males and 5 females) were asked to sing messa di voce exercises on eight scale tones, performed in three consecutive conditions: baseline (‘before’), flow ball phonation (‘during’), and again without the flow ball (‘after’). These conditions were repeated eight times in a row: one scale tone at a time, on an ascending whole tone scale. Audio and electroglottographic signals were recorded using a Laryngograph microprocessor. Vocal fold contacting was assessed using three time-domain metrics of the EGG waveform, using FonaDyn. The quotient of contact by integration, Qci, the normalized peak derivative, QΔ, and the index of contacting Ic, were quantified and compared between ‘before’ and ‘after’ conditions. ResultsEffects of flow ball exercises depended on singers’ habitual phonatory behaviours and on the position in the voice range. As computed over the entire range of the task, Qci was reduced by about 2% in five of ten singers. QΔ was 2–6% lower in six of the singers, and 3–4% higher only in the two bass-baritones. Ic decreased by almost 4% in all singers. ConclusionOverall, vocal adduction was reduced and a gentler vocal fold collision was observed for the ‘after’ conditions. SignificanceFlow ball exercises may contribute to the modification of phonatory behaviours of vocal pressedness.