The effect of asthma on phonation: a controlled study of 34 patients.

The effect of upper respiratory tract diseases on phonation has been reviewed, but little is known about the influence of lower respiratory tract diseases. In particular, the effect of asthma as a reversible obstructive small-airway disease on phonatory variables is not yet clear. We conducted a cross-sectional controlled study to evaluate the quality of phonation in a group of 34 adults with untreated mild to severe persistent asthma who were seen at the Ghaem Hospital in Mashhad, Iran.