The origin of cough sounds.

We have analyzed the origin of the first and second cough sounds recorded by tussiphonography. About 10,000 tussiphonograms were performed in about 1,000 healthy and diseased subjects. Changes in the first cough sound are due to pathological processes in the airways, for example, the presence of mucus or acute inflammatory disease. The first cough sound may then become divided. In bronchial asthma the first sound is also abnormal because of the narrowed airways. The origin of the second sound becomes clear by its absence in patients after laryngectomy or in those with paralysis of the vocal folds. The reappearance of the second cough sound may indicate rehabilitation of the vocal folds. With laryngotracheitis there is a pattern of multiple sounds. In patients with cough of psychogenic origin, the second sound is absent and cough sounds "bovine". Treatment of patients with bronchodilating drugs did not improve their pathological cough sounds in spite of improvement in airway obstruction.