"1)The length and intensity of inspiration and expiration are equal.
2) There is an audible gap between the inspiratory and expiratory phase sounds.
3) Expiratory phase is loud & high pitched.
Similar sounds can be heard in healthypeople
by listening over the trachea or bronchus.
In healthypeople however
these sounds are not conducted to the chest wall since they are attenuated by air filled alveoli and lung parenchyma.
In the presence of consolidation however the sound of air flow in the bronchi is conducted more effectively to the chest wall and bronchial rather than vesicular breath sounds are heard.
For bronchial breathing to be present
the bronchus to the diseased area MUST be patent. "