A test of the practical value of estimating breath sound intensity. Breath sounds related to measured ventilatory function.

Each of four examiners performed standardized physical examinations on a group of patients who had just undergone tests of ventilatory function. The intensity of breath sounds heard with deep inspiration was graded on a rating scale of 0 to 4; the grades in six areas of the chest were added to give a total score, with possible values ranging from 0 to 24. Correlation of breath-sound scores with percentage of predicted forced expiratory volume in one second (FEV1) was significant at the 1 percent level for all of the examiners. Differences between the examiners in their assessment of breath sounds were not statistically significant. Grading the loudness of breath sounds was a poor screening test for mild ventilatory abnormality, but normal breath sounds nearly excluded the possibility of severe reduction in the FEV1. Definitely reduced breath-sound intensity was strong evidence for the presence of obstructive pulmonary disease.