This is
the sound heard over the chest at a distance from large airways.
It is a
"soft" sound that has been compared to the sound of wind blowing
through the leaves of a tree.
This is the
most common sound heard in the absence of lung disease.
Vesicular sounds are
the most common sounds heard over the chest. They are present at sites that are
at a distance from large airways. While the term vesicular has been criticized
because it is unlikely that any sound is produced in the "vesicles"
i. e. alveoli, it is still a useful term to describe the sounds heard when the
stethoscope is over lung parenchyma at a distance from large airways. The vesicular
sound is a soft sound that has been compared to that of wind blowing through trees.
It is louder in inspiration than expiration. In the time expanded waveform analysis
an almost random undulating pattern is seen in inspiration. The expiratory sound
is of relatively low amplitude. The vesicular sound is commonly decreased in chronic
obstructive lung disease. It is also decreased over sites of pneumonia in the
early stages of the illness. It is usually, but not always, decreased or absent
in conditions where the ventilation to an area of lung is impaired: e. g. pneumothorax,
misplaced endotracheal tube, mucus plugging.