The term “vesicular breath sound” was coined by René Laennec, the inventor of the stethoscope. The quality of vesicular breath sounds can be likened to the sound of rustling dry leaves, a gentle and continuous noise. This shorter expiratory phase is due to the high-pitched sounds produced in the latter two-thirds of expiration being filtered out, leaving the low-pitched sounds more prominent. Notably, the expiratory phase in vesicular breathing is shorter than the inspiratory phase. Characteristically, it is soft and has a low pitch (low frequency). The vesicular breath sound is recognized as the normal breath sound heard over most lung fields during auscultation. Normal Breath Sounds Vesicular Breath Sounds Understanding this fundamental concept is crucial for discussing the origin of abnormal sounds in different conditions, which will be explored in subsequent sections of this article. This altered sound is referred to as the vesicular breath sound. During this journey, certain high frequencies of the sound are absorbed (attenuated), altering the sound’s character.The bronchial breath sounds, originating in the major airways, must traverse through various tissues, including the air in the bronchi and bronchioles, and the walls of the alveoli, to reach the body’s surface, where they are auscultated.The vesicular breath sound is what is normally heard over the chest wall, in the respiratory areas.The bronchial breath sound is naturally produced at the trachea.This is distinct from what is commonly referred to as the ‘normal’ breath sound, which is vesicular. When auscultating at the trachea, the sound typically heard is known as bronchial breath sound.The air flow velocity in the alveoli is too low to create the turbulence necessary for audible sounds during auscultation. Mechanism of Breath Sounds Productionīreath sounds are generated in the major airways, specifically the trachea and the major bronchi.Ĭontrary to a common misconception, alveoli, the small air sacs in the lungs, do not produce these sounds. Key Guides for Auscultationĭuring auscultation, the following three key questions should guide the examination: Intensity of Breath Sounds:Īre the breath sounds louder, softer, or normal compared to standard breath sounds? Character of Breath Sounds:ĭo the breath sounds sound normal or are there unusual qualities? Presence of Adventitious Sounds:Īre there any extra or unusual sounds that are not typically present in normal breathing?īy focusing on these aspects, a more accurate assessment of the patient’s respiratory health can be achieved. Overexerting a patient with respiratory difficulties is counterproductive. This consideration is particularly important as detailed respiratory examination is often performed when a respiratory ailment is suspected. Requests for deep breaths should be minimal to avoid exhausting the patient. Auscultation can usually be conducted while the patient breathes normally. Patient Comfort:Įnsuring the patient’s comfort is essential. In cases where the patient has a hairy chest, moistening the area with warm water may help. This approach is preferred to avoid listening through clothing, which can create misleading friction sounds. The stethoscope should make direct contact with the patient’s bare skin. However, the anterior chest regions can still be examined when the patient is lying down. Ideally, the patient should be seated during auscultation to allow complete access to all chest areas.

To effectively perform auscultation, certain conditions and practices should be observed: Quiet Environment:Ī quiet setting is crucial for auscultation as it aids in clearly hearing the breath sounds. Most of the breath sounds in this article were recorded using a Littmann 3200 electronic stethoscope, and some using the Littmann CORE digital stethoscope that I currently use, widely respected electronic stethoscopes for auscultation. For an experience similar to using a stethoscope, it is advisable to use headphones. I encourage you to listen to all the audio samples on this page. This article provides detailed descriptions of different respiratory sounds, accompanied by audio recordings for educational purposes.

Listening to breath sounds, auscultation, is a crucial clinical method for assessing respiratory problems in patients.

Coarse lung sounds