Respiratory Sounds

Auscultation of the chest is a very old diagnostic method. Originally, it was performed by the examiner
directly hearing into the patient's chest, and this practice dates back to the time of Hippocrates.
Recent acoustic research sometimes can’t find the explanation for a term that is supposed to have a
pathophysiological basis, but that has been passed down through generations with medical over
time.The original description of lung sounds was based on comparing acoustic phenomena that was
heard in the chest with gross lesions autopsy. Subsequently, the interpretation of these findings is
based on functional rather than anatomical analysis. Auscultation became an invaluable diagnostic
method. With the advent of radiological images, increasingly sophisticated, computerized tests of lung
function, rapid arterial blood gas analysis, endoscopic studies airway and percutaneous biopsies of
pleura and lung; the practice, with method and timing of chest auscultation, has lost presence. In
addition, the nomenclature of respiratory sounds is sometimes confusing and the terminology
proposed by international committees, little known. One objective of the article is to give a
pathophysiological basis of noise based on modern computer-assisted studies which have enabled
accurate recording and sound analysis techniques. The other objective is to provide a practical and
useful tool to understand and correlate what you hear, with the pathophysiological basis, the
underlying condition that generates the phenomena and streamline the diagnostic work. Technology
has impacted medical auscultation with computerized equipment that allows to collect, analyze and
study sound waves in a realistic way and never before seen. This technological development enables
and improvement in auscultation knowledge in order to understand more and better findings. But this
development should not pretend to cram sophisticated, expensive and unnecessary medical
equipment. Auscultation of the lungs with a simple stethoscope, in day to day work and to the bedside
of the sick, is part of the physical assessment. We must remember that it is a tool whose effectiveness
depends on the rest of the physical examination and medical history.