Analysis of the cough sound: an overview.

Coughing is presented by a sudden air expulsion from the airways which is characterized by a typical sound. This sound is so characteristic that it allows identification of the cough and its distinction from other vocal manifestations. The cough sound is a very important symptom of well over 100 diseases and other conditions of medical significance. Changes in its character may have a considerable value in identifying the mechanisms of airway pathology present in respiratory diseases. The cough sound gives information about the pathophysiological mechanisms of coughing by indicating the structural nature of the tissue during therapy that leads to certain patterns of cough. Similarly the character of the cough sound gives information about the behaviour of the glottis and whether the glottis behaves differently in different pathological conditions. Analysis of the cough sound record has significant value in prognosis because its changes may indicate the effectiveness of therapy or the progress of disease. Despite recent progress in cough sound research the attention paid to this interesting physiological and clinical problem is still not sufficient to solve completely various open questions, including our correct knowledge of the mechanism of creation of cough sounds.