[…] friction rub), dullness to conventional percussion was most accurate for diagnosing pleural effusion (summary positive likelihood ratio, 8.7; 95% confidence interval, 2.2
[ncbi.nlm.nih.gov]
The physician will listen to the chest with a stethoscope for signs of decreased breath sounds or a pleural friction rub—the sound of pleura rubbing together during respiration
[msdmanuals.com]
[…] evaluated in the included studies (conventional percussion, auscultatory percussion, breath sounds, chest expansion, tactile vocal fremitus, vocal resonance, crackles, and pleural
[ncbi.nlm.nih.gov]