Introduction
Auscultation is the age-old diagnostic technique used to identify variations in airflow through the airways and lungs. It's a simple, non-invasive, safe, and cost-effective diagnostic procedure. An auscultatory examination can identify most of the respiratory system abnormalities. Bronchophony, or broncholiquy, is abnormal sound transmission through the lungs or bronchi. They are determined through auscultation of the chest. Normally during auscultation, when the physician moves the head of the stethoscope to the periphery of the lungs, the sound becomes less distinct; however, in certain pathologies, auscultation of the chest peripheries will produce a more distinct and louder sound. It can be determined by asking the patient to repeat words like "ninety-nine" or "sixty-six," The sound will remain the same or even louder than in the center of the lungs for a bronchophony-positive person, and the sound loses its intensity in the peripheries for a healthy individual. This deviation from normality can be explained by an area of consolidation, as seen in pneumonia or solidification around the bronchioles and alveoli due to a lung tumor.
What Is Bronchophony or Broncholiquy?
Bronchophony means sounds from the bronchus. It doesn't mean these sounds have to be searched over the bronchus or the trachea; it becomes a sign only when heard over an unusual place. The voices from the lungs are a sign by which the physician can judge the state of the lungs, whether it's healthy or not. In a healthy individual, the sounds produced from the larynx will propagate to the tracheal air and further into the bronchial tubules. On auscultation over the trachea and the upper sternum, the voices heard will be louder because they are confined to a narrow tube than those heard with the ear in an open space. Further, as we move the head of the stethoscope to the peripheries first on the bronchial tubules, the voice will still be heard but will not be as loud as in the previous position and will be less distinct. Moving to smaller branches will produce only confused, muffled voices. Finally, the voice is lost in the vesicular structure, and only a fremitus produced throughout the chest can be heard. The voices heard will be muffled and distant in the lung peripheries.
The main reason for the decreased intensity of the sound moving to the periphery is that the smaller bronchial tubules and the vesicular structure do not afford enough space to carry the vibrations; also, they have less tense tunics that are more membraneous, which are not adapted to reflect sound. Thus, the anatomical structure of the lungs and its different parts is responsible for producing different varieties of vocal resonance observed while auscultating the chest.
In a normal healthy individual, on the application of the stethoscope to the trachea or the larynx, sounds as loud or even more than that from the patient's mouth can be heard (natural bronchophony). This phenomenon exists in the chest peripheries only in diseased conditions. Natural bronchophony can be heard in the upper part of the sternum, upper axilla region, and interscapular region. The vocal resonance differs in different individuals, and the cause of this considerable variation is not obscure. In lean individuals, it is sharp, loud, and most extensive, and they have a sharp treble in their voice. Natural bronchophony will be loud and distinct in the tracheal, upper sternum, upper axial, and interscapular regions; also, they might extend to the mesial scapular, infraclavian and mammary areas. It is therefore marked in young women and children. On the other hand, an obscure and confined bronchophony is observed in people with enough fat and muscles around their chest. They do not have enough space to transmit the vibrations through the small tubules, and this explains the change in tones in the same individual may produce considerable variation in the bronchophonic resonance.
What Is the Role of Bronchophony in Disease Conditions?
Changes in vocal resonance observed during auscultation can indicate signs of certain diseases. In a healthy state, natural bronchophony exists only over the area of the bronchi and trachea, which are large spaces and can easily transmit sound vibrations and as we move to the periphery, that is, to the branchial tubules and the vesicular structure, these sounds become confined and silenced due to the narrow tubes and the surrounding structures, however in conditions like inflammation, edema, sanguineous and tubercular infiltration are often associated with an accidental bronchophony in the peripheries. The presence of solidification and consolidation will enable the sound vibrations to be conducted to the periphery, and the accidental bronchophony is heard.
Consolidation of the lungs seen in pneumonia, pleural effusion, lung tumors, etc., are some disease conditions associated with abnormal bronchophony. Thus when broncholiquy (bronchophony) is heard in any other part of the lung other than the normal bronchophonic situations indicates a solidification of the lung. Because of this solidification, sound transmission to the surface takes place. It may arise from either the accumulation of solid mass or liquid inside the lungs.
How Is Bronchophony Detected in a Disease Condition?
Auscultation is the simplest and most efficient diagnostic technique followed over the years to recognize lung abnormalities. Bronchophony is a general sign detected through auscultation in patients with lung solidification and consolidations. On identifying abnormal bronchophony, further tests are suggested.
During the physical examination, the physician auscultates areas of both lungs; meanwhile, the patient is asked to repeat the word ninety-nine or sixty-six. In normal bronchophony, these words were distinct only in the supra sternal, upper axillary, and interscapular regions and in the periphery; however, the sound was less distinct and muffled; however, abnormal or accidental bronchophony with the distinct sound heard over the peripheries of the lungs indicating a consolidation or liquefaction.
Conclusion
Bronchophony in an abnormal location gives only a vague idea about the existence of an underlying disease condition. It suggests further investigative tests rather than the main diagnostic basis. To identify abnormal bronchophony, the physician should be thorough with the normal sounds and where the normal bronchophony is observed.
