Transactions of the ASAE vol:47 issue:1 pages:351-356
The relation between air quality and respiratory health and comfort in humans and animals has been widely shown. In general, a state of respiratory discomfort in everyday indoor and outdoor life results in an increase in audible acoustic symptoms. The general concept of sound analysis as an objective, contactless, and non-invasive biomarker for aerial stressors was studied on free-field registered cough sounds of 12 Belgian Landrace piglets. A citric acid-induced cough sound-recognition algorithm with a recognition percentage of 95% was applied to cough sounds registered in the presence of distinct types of aerial factors: irritating gas (ammonia), respirable particles (dust), and climate (temperature). The recognition percentage for all aerial factors exceeded 90% and averaged 94%. Therefore, it was concluded that sound analysis could provide an effective biomarker for all three types of aerial factors. The generality of the biomarker is speculated to arise from the common mechanism involved in protective cough, which will stand as long as no physical changes (e.g., growth, disease) to the state of the respiratory system occur. The results suggest that sound analysis as a biomarker of the respiratory state may be integrated into room or personalized air ventilation control to improve respiratory comfort of animals.