TABLE 1.

Thoracic auscultation (AUSC) scoring system and categorizations used to explore the impact of different lung sounds classification for distinguishing calves with and without bronchopneumonia.

Score	AUSC findings	Description	AUSC1	AUSC2	AUSC3
0	Normal breath sounds	Soft blowing sounds, longer and louder on inspiration than on expiration. In heavier subjects, the sound from expiration may be nonaudible (Lung sound file 1)	−	−	−
1	Increased breath sounds	Increase in loudness of breath sounds mainly on inspiration but also on expiration. The difference between inspiration and expiration is always identifiable (Lung sound files 2 and 3)	+	−	−
2	Signs of bronchial disease: (a) Wheezes or (b) Crackles in at least 1 auscultation site	(a) Variable‐toned, intermittent, or continuous musical whistling sounds (“huin”) 35 that are usually heard on expiration but can also be heard on inspiration (Lung sound file 4) (b) Crepitating nonmusical sounds (“knack”) 35 (Lung sound file 5)	+	+	−
3	Signs of lung consolidation: Increased bronchial sounds in at least 1 auscultation site	High and harsh audible tone like what is usually possible to hear during trachea auscultation. Difficulty in assessing the difference in tone between expiration and inspiration (Lung sound file 6)	+	+	+
4	Signs of pleuritis: Pleural friction rubs	Grating sounds during inspiration and first phase of expiration (Lung sound file 7)	+	+	+

Note: For this study, we evaluated the accuracy performance of respiratory sounds by categorizing them into 3 different models: AUSC1 (score of 0 [negative] vs ≥ 1 [positive]), AUSC2 (score of 0 or 1 [negative] vs ≥ 2 [positive]), and AUSC3 (score ≤ 2 [negative] vs ≥ 3 [positive]). +: Sound considered in categorization of positive cases. −: Sound not considered in categorization of negative cases.