Auscultation: A Clinical Perspective

Auscultation and the Stethoscope: A Clinical Perspective

by: lim ju boo alias lin ru wu (林 如 武)

Introduction:

Ancient civilizations started listening to breath sounds for diagnosis appear in the Ebers Papyrus of Ancient Egypt (c. 1500 BCE) and the Hindu Vedas (c. 1400–1200 BCE).  In  ancient Greece (c. 440–360 BCE), Hippocrates practiced "immediate auscultation" by applying his ear directly to the patient's chest. He described sounds such as the "frictional rub" of pleuritis and "succussion splash" (the sound of fluid in the chest when a patient is shaken).

In the late Renaissance to 18th Century William Harvey (1628) provided the first detailed description of heart sounds as "two clacks of a water bellows".  Robert Hooke (17th century) predicted that internal sounds could reveal which "internal parts of bodies" were out of order.  James Douglas (1715) and William Hunter (1757) recorded specific heart murmurs heard even at a distance from the patient

Thus, in ancient times physicians began actively listening to body sounds (auscultation) by merely placing their ears on the body without needing any stethoscope as a diagnostic practice until  the early 19th century when the stethoscope was invented as a more convenient method.  Before the stethoscope, some basic forms of listening (immediate auscultation) involved placing an ear directly to the body, a practice noted as far back as Hippocrates, as I have already mentioned. The pivotal shift occurred in 1816 when French physician René-Théophile-Hyacinthe Laennec invented the first stethoscope in Paris.

He used a rolled tube of paper to listen to a patient's heart and lungs, finding the sounds clearer and the method more effective and discreet than immediate auscultation . This invention allowed physicians to listen to internal sounds with unprecedented clarity, leading to the development of a systematic understanding of the sounds produced by various heart and lung conditions.

 I have personally heard exactly the same sounds produced by the body without needing any stethoscope by merely placing my ears over the hearts of children with congenital heart problems  when their parents brought them to see me when I was having my dinner in a restaurant. Surely you don't expect me to carry a stethoscope to a restaurant, to the shop or to the supermarket or when I needed to attend to a unexpected medical emergency such as in a road accident.  Without any stethoscope,  I merely placed my ears on various regions on the precordium  (regions in the chest wall over the heart), and I could distinctly hear the murmurs and even classified the types and their underlying causes or pathology. I shall describe these pathological sounds later as I write along here.  The stethoscope  merely made it more easier and convenient for physicians.  Thus, the stethoscope was quickly adopted, and by the mid-19th century, listening to body sounds had become a basic  component of the physical examination

Auscultation to most ordinary clinicians view it as one of their most venerable and fundamental clinical skills in medicine despite the fact we now use far more advanced electronic, laboratory,  imaging and even molecular diagnostic techniques to diagnose especially for differential diagnosis and in cases where the diseases produce no sound such as diabetes, inflammation, fever, infection, cancer, a fracture (x-ray is needed), or malaria (thick stained blood film under a microscope is needed), or high blood pressure (except those sounds of Korotkoff heard when measuring blood pressure using a mercurial blood pressure instrument). Not all diseases can be diagnosed using a stethoscope. 

  

Auscultation is the act of listening to internal bodily sounds to evaluate physiological processes and discern potential pathology. Since René Laennec's invention of the stethoscope in 1816, this technique is indispensable in the bedside examination of patients, particularly in the assessment of the respiratory and cardiovascular systems, as well as in the identification of vascular abnormalities such as bruits. Despite the emergence of advanced diagnostic technologies which we now use in major hospitals with technological facilities, auscultation continues to maintain a primary role due to its simple, immediacy, non-invasiveness, and capacity to yield vital diagnostic insights (1,2).

 

Let us now have a look at:  

Auscultation of the Respiratory System  

 

When appraising the thorax, auscultation enables the clinician to evaluate airflow dynamics within the lungs and detect abnormal or adventitious sounds. The primary normal respiratory sound is the vesicular breath sound, which is audible over the majority of lung fields. These sounds are characterized by their soft and low-pitched quality, reminiscent of a gentle rustling. They manifest during active inhalation as air traverses into the bronchi and alveoli, persisting through passive exhalation driven by alveolar elastic recoil. The phases of these sounds can be broadly delineated as the tubular component, succeeded by the alveolar phases during both inspiration and expiration (3).

 

Any deviation from this normative pattern may signify underlying pathology. For instance, bronchial breath sounds, if detected in peripheral lung fields, may indicate consolidation, as seen in pneumonia, while adventitious sounds such as crackles, wheezes, or rhonchi may reflect conditions such as pulmonary fibrosis, asthma, or chronic obstructive pulmonary disease (3,4).

Auscultation of the Cardiovascular System  

Let  us now go into listening to the heart.  Cardiac auscultation entails the act of listening to the heart using a stethoscope to assess valve functionality and identify abnormal blood flow patterns. Both the diaphragm and the bell of the stethoscope are employed: the diaphragm for high-pitched sounds such as the first (S1) and second (S2) heart sounds, and the bell for low-pitched sounds such as the third (S3) and fourth (S4) heart sounds, or certain diastolic murmurs (5).

A systematic approach is imperative. The examination typically commences at the apical impulse and progresses to the lower left sternal border, the right and left upper sternal borders, and ultimately to the axilla when indicated. Various patient positions, including supine, sitting forward, and left lateral decubitus, are often utilized to accentuate specific sounds (6).

The normal heart sounds comprise S1, produced by the closure of the mitral and tricuspid valves, and S2, resulting from the closure of the aortic and pulmonic valves. Physiological splitting of S2 during inspiration is commonplace and generally benign. Abnormal sounds encompass S3, associated with rapid ventricular filling and often suggestive of heart failure, and S4, which arises from atrial contraction against a stiff ventricle, potentially indicating left ventricular hypertrophy or ischemia (7).

Murmurs represent additional sounds generated by turbulent blood flow across valves. They are described by their timing within the cardiac cycle, intensity, pitch, location, and radiation. Systolic murmurs occur between S1 and S2 and may be further classified as midsystolic, holosystolic, or late systolic. Diastolic murmurs transpire between S2 and S1, while continuous murmurs extend across both systole and diastole. Noteworthy examples include the holosystolic murmur of mitral regurgitation radiating to the axilla, the pansystolic murmur of tricuspid regurgitation accentuated during inspiration, the harsh pansystolic murmur of a ventricular septal defect at the left sternal border, and the Austin Flint murmur indicative of severe aortic regurgitation (8,9). Innocent murmurs, such as Still’s murmur in children, may also be encountered and must be differentiated from pathological murmurs.

To standardize assessment, systolic murmurs are classified from I to VI, with grade I being scarcely perceptible and grade VI audible without the stethoscope in contact with the chest. Murmurs graded IV or higher are typically associated with a palpable thrill (5). The early identification of abnormal heart sounds is of paramount clinical importance, as it enables timely intervention, mitigates morbidity, and enhances patient outcomes (7).

 

Let us now go into listening to stenosed blood vessels. Auscultation of Blood Vessels: Bruits

Beyond the examination of the lungs and heart, auscultation is useful for evaluating major blood vessels. A bruit is an aberrant, blowing or whooshing sound discerned over an artery, resulting from turbulent blood flow through a narrowed or partially obstructed vessel. In contrast to heart murmurs, bruits are extracardiac and generally signify vascular pathology.

Common sites for the auscultation of bruits encompass the carotid arteries in the neck, the abdominal aorta, the renal arteries, as well as the iliac and femoral arteries. Aetiological factors include arterial stenosis, often attributable to atherosclerotic plaque, or other obstructive lesions. Clinically, the identification of a carotid bruit holds particular significance, as it may indicate carotid artery disease and herald an elevated risk of stroke (10). Similarly, abdominal or renal bruits can denote aneurysm or renovascular hypertension, conditions necessitating further imaging and prompt intervention.

 

Besides listening to the symptoms the patients tells, looking for signs physically and taking medical history, auscultation and the utilization of the stethoscope is the basic element of clinical examination. Whether assessing vesicular breath sounds, differentiating complex cardiac murmurs, or detecting vascular bruits, auscultation can yield basic interpretation  into the underlying physiology and pathology of the patient. While contemporary imaging and other electronic diagnostic techniques, including genetic and molecular analysis and other highly sophisticated blood, urine and other biological examination that  provide highly advanced enhanced precision these days with the advancement of medicine through research, the art of attentive listening remains the simplest basic for bedside evaluation, early diagnosis, and clinical decision-making. Mastery of this skill not only augments diagnostic accuracy using other more advanced approaches but also sustains the tradition of listening to body sounds since the time of Hippocrates. Engaging in this simple process allows for the exploration of subtle shades that may escape more mechanized assessments.

Moreover, the ability to discern minute variations in sound can unveil a myriad of conditions, from valvular heart diseases to systemic ailments, where the implications of timely recognition can be life-altering. This diagnostic skill transcends routine practice and has now become an art form, one that demands both patience and profound attentiveness. besides listening carefully what the patient tells us about their complaints and medical history we take, which to me is the most important because we can already diagnose with 75 % accuracy without using any stethoscope or using other advanced methods that are available only in tertiary and teaching hospitals.  

As our inroads in medicine evolves through research and studies,  integrating technological advances with traditional methodologies, the role of auscultation should not be relegated to obsolescence. Rather, it should be viewed as an essential complement to innovative diagnostic tools, serving to enrich the clinician’s toolkit. The harmony between advanced imaging and the traditional technique of auscultation ensures a holistic approach to patient care, empowering practitioners with a comprehensive understanding of health dynamics.

We may say, as the complexities of modern medicine continue to expand, the fundamental principles of clinical assessment such as listening carefully to the complaints of the patient, taking their medical history, and conducting simple clinical examinations remain steadfast. The mastery of auscultation, with its capacity to provide immediate feedback and understanding, is the basic asset in the clinician's repertoire. It not only enhances primary diagnoses but also reinforces the humanistic aspects of medical practice, ensuring that care remains not only effective but deeply empathetic. Thus, embracing and refining the art of auscultation as ones of them, this will continue to be paramount as we navigate the intricate interplay between health and healing in the evolving scenario of healthcare.

Let me classify the sounds we can hear in a table form. Sorry for the table congestion as I have no space in this simple article I write as I need to squeeze all of them in. 

 

System	Normal Sounds		Abnormal Sounds	Clinical Significance
Respiratory	Vesicular breath sounds: soft, low-pitched, rustling, heard across most lung fields		Bronchial breath sounds in periphery; Adventitious sounds (crackles, wheezes, rhonchi)	Consolidation (pneumonia), asthma, COPD, fibrosis
Cardiac – Heart Sounds	S1: closure of mitral & tricuspid valves; S2: closure of aortic & pulmonic valves (physiological splitting in inspiration)		S3: rapid ventricular filling (HF); S4: atrial contraction against stiff ventricle (LVH, ischemia)	Heart failure, hypertrophy, ischemic heart disease
Cardiac – Murmurs	None		Systolic, diastolic, or continuous murmurs, described by timing, pitch, intensity, radiation	Valvular disease (e.g., MR, TR, VSD, AR, AS)
Cardiac – Murmur Examples	Innocent murmurs (e.g., Still’s murmur in children)		Austin Flint (severe AR); Graham Steell (pulmonary regurgitation); Holosystolic MR/TR murmurs	Differentiates benign vs. pathological murmurs
Vascular	No bruit		Bruit: blowing/“whooshing” sound over artery	Carotid bruit (stroke risk), renal bruit (renovascular HTN), abdominal bruit (aneurysm)

Clinical Pathway of Auscultation: 

 

Step 1: Preparation

Ensure a quiet environment.

Patient positioned appropriately (supine, sitting, left lateral, etc.).

Use diaphragm and bell of stethoscope correctly.

 

Step 2: Systematic Listening

Respiratory system: Listen over multiple lung fields (anterior, posterior, lateral).

Cardiovascular system: Listen systematically over the four valve areas (aortic, pulmonic, tricuspid, mitral) and axilla if needed.
Vascular system: Listen over carotids, abdominal aorta, renal, femoral, and iliac arteries when indicated.

 

Step 3: Identify Normal vs. Abnormal

Respiratory: Vesicular vs. bronchial/adventitious sounds.

Cardiac: S1, S2 normal; presence of S3, S4, murmurs.
Vascular: Presence or absence of bruits.

 

Step 4: Characterization of Abnormal Sounds

Respiratory: Type of adventitious sound (crackles, wheezes, rhonchi).

Cardiac murmurs: Timing (systolic, diastolic, continuous), pitch, intensity (I–VI), location, radiation, quality.
Bruits: Site, intensity, duration.

Step 5: Correlate with Clinical Context
Match auscultatory findings with symptoms (dyspnea, chest pain, syncope).
Integrate with physical signs (cyanosis, edema, pulse quality, BP changes).

 

Step 6: Clinical Decision

Normal findings → reassurance and routine monitoring.

Abnormal but benign (e.g., Still’s murmur) → observation.

 

Pathological findings → further investigations:

 

Respiratory: Chest X-ray, CT, spirometry.
Cardiac: Echocardiography, ECG.
Vascular: Doppler ultrasound, CT angiography.

Step 7: Management and Follow-up

Use auscultatory findings as early diagnostic evidence.

Guide medical/surgical treatment decisions.
Monitor progression or resolution during follow-up.

 

A Medical Psalm: The Shepherd’s Auscultation

 

“The Lord is my Shepherd; I shall not want. He makes me lie down in green pastures; He leads me beside still waters; He restores my soul.” 

(Psalm 23:1–3)

So too, the physician with stethoscope in hand becomes a shepherd of the patient. To auscultate is to pause, to lean in, and to listen, not only to the rhythms of heart and lung, but to the unspoken fears and silent hopes of the one who suffers.

1. The quiet room is the green pasture.

2. The still diaphragm of the stethoscope is the still water.

3. The sounds of the heart and lungs are the voice of the flock, calling for guidance.

When the physician listens with humility, wisdom, and compassion, auscultation becomes more than a diagnostic tool, it becomes a ministry of healing. As the Good Shepherd restores the soul, the attentive clinician restores the trust, dignity, and hope of the patient.

 

Auscultation remains a vital pathway, uniting clinical science with the healing art of listening. Its practice, structured, disciplined, and compassionate, reminds us that medicine is not only about discovering pathology but also about shepherding life with care. In the stillness of auscultation, the voice of both body and soul can be heard.

 

References

 

1. Laennec RTH. De l’Auscultation Médiate. Paris: J.-A. Brosson & J.-S. Chaudé; 1819.

 

2. Mangione S, Nieman LZ. Cardiac auscultatory skills of internal medicine and family practice trainees: a comparison of diagnostic proficiency. JAMA. 1997;278(9):717–22.

 

3. Vukanovic-Criley JM, et al. Competency in cardiac examination skills in medical students, trainees, physicians. Arch Intern Med. 2006;166(6):610–6.

 

4. Shaver JA. Cardiac auscultation: a glorious past—and it does have a future! Circulation. 1995;91(4):1256–9.

 

5. Roy D, Sargeant J. The disappearing art of auscultation: a call to action. Med Teach. 2012;34(7):568–70.

 

6. Chizner MA. Cardiac auscultation: rediscovering the lost art. Curr Probl Cardiol. 2008;33(7):326–408.