Pre- and Poststimulation Study on the Phonatory Aerodynamic System on Participants with Dysphonia

The purpose of this preliminary investigation was to examine the sensitivity of the Phonatory Aerodynamic System (PAS) in an exploratory investigation that looked at the effects of stimulation training (pre and post stimulation) on 20 participants with vocal complaints. The following parameters were tested: subglottal pressure, sound pressure level, airflow, and fundamental frequency.

A total of 20 participants with vocal complaints performed the Voicing Efficiency protocol on the (PAS). The participants spoke into a mask and repeated the utterance /papapa/ five times on a single breath for three sets (pausing between sets). Measurements of the parameters were recorded on the PAS. Subsequently, the participants were given stimulation training involving the coordination of respiration and phonation and purposely engaging the abdominal muscles upon phonation. They repeated the same PAS task, using the training. Their parameters after training were compared to normal values to determine improvements post stimulation results.

The participants showed improvement in a number of parameters post stimulation, especially subglottal pressure and fundamental frequency (i.e., closer to normal values in comparison with pre-stimulation results) and on the graphic readouts; the respiratory waveforms showed greater consistency and evenness on certain parameters compared with those in the pre-training graphs. Perceptually, the participants' voices revealed reduced noise and strain.

Post stimulation, a number of parameters improved towards normal values; the respiratory graphic waveforms were more consistent and even, and perceptually improved vocal quality was noted by judges and participants.