The Effect of a Vocal Loading Test on Cough and Phonation in Patients With Chronic Cough.

OBJECTIVE/HYPOTHESIS: Talking is a significant trigger for cough in patients with chronic cough; however, the stimulus required to trigger cough has not been quantified. The aim of this study was to examine the effect of a vocal loading task on phonation and cough behavior in patients with chronic cough and identify change following therapy.

STUDY DESIGN: This is a prospective observational study.

METHODS: This study involved 33 patients with chronic cough. Participants were assessed with the lingWAVES Vocal Loading Test protocol before and after intervention for chronic cough.

RESULTS: At baseline, almost 40% of patients had impaired vocal function and were unable to complete the vocal loading test. This improved following therapy, with 94% of patients being able to complete the test at follow-up. There was difficulty maintaining phonation, with 60% of the task unvoiced at baseline. This improved following therapy. The vocal loading test triggered coughing in 58% of patients; however, this improved following intervention. Acoustic measures during the vocal loading test did not change following therapy.

CONCLUSION: Phonation is an important trigger for cough. Patients with chronic cough demonstrated impaired performance on tests of vocal loading. Most parameters improved following therapy.