Analysis of the Cough Sound

Cough is readily recognized by the human ear and can easily be distinguished from other upper airway sounds such as speech, laughing, throat clearing, and snoring. In addition, individuals can sometimes be recognized by the characteristics of their cough and specific cough qualities have been attributed to different chest conditions. Medical textbooks describe cough by a number of descriptors (e.g., dry, moist, productive, brassy, bovine, barking, rattling, hoarse, wheezy, loose, etc), which can be broadly divided into those coughs produced with and without the presence of sputum within the airways. A recent systematic study of cough descriptors using cluster analysis (1) has confirmed that commonly used terms do indeed divide cough into those associated with sputum (moist, productive, rattling, and loose) and those without sputum production (dry, brassy, barking, and hoarse). Moreover, although some practitioners can also recognize a wheezy quality to cough, there was a very limited ability to recognize individual chest diseases by their cough characteristics.