The origin of cough sounds

Area of Science:

• Pulmonology
• Otolaryngology
• Acoustic Analysis

Background:

• Cough sound analysis using tussiphonography is an emerging diagnostic tool.
• Understanding the acoustic properties of cough sounds can provide insights into underlying respiratory and laryngeal conditions.

Purpose of the Study:

• To analyze the origin of the first and second cough sounds recorded via tussiphonography.
• To correlate specific cough sound characteristics with various pathological conditions.

Main Methods:

• Analysis of approximately 10,000 tussiphonograms from 1,000 healthy and diseased subjects.
• Correlation of acoustic features with clinical diagnoses including airway obstruction, vocal fold paralysis, and psychogenic cough.

Main Results:

• First cough sound alterations are linked to airway pathologies like mucus or inflammation, and conditions such as bronchial asthma.
• The second cough sound's presence or absence is associated with vocal fold integrity, being absent in laryngectomized patients or those with vocal fold paralysis.
• Specific patterns like multiple sounds in laryngotracheitis and absence of the second sound in psychogenic cough ('bovine' cough) were observed.

Conclusions:

• Tussiphonography effectively differentiates cough sound origins, linking the first sound to airway status and the second to vocal fold function.
• The study highlights the potential of cough sound analysis in diagnosing respiratory and laryngeal disorders.
• Bronchodilator treatment did not resolve pathological cough sounds despite improving airway obstruction, suggesting non-airway components in some cough conditions.