Basics of Lung Sounds

This module provides students with the opportunity to hone their auscultation skills for important breath sounds through recordings, waveform tracings, and concise lessons. Learners are presented with lessons for vesicular sounds, crackles, wheezes, rhonchi, pleural rubs, and bronchial sounds.

Using this course

This comprehensive lung sounds course will help you master the basics with text, audio recordings and a torso diagram. But don’t overlook the waveform video -- it can be an important asset when visualizing various lung sounds including normal vesicular breath sound, crackles, wheezing noise rhonchi, pleural rubs and bronchial noises.

After completing a lesson, use the lesson table of contents to navigate to another lesson.

When all lessons have been completed, we recommend using the auscultation practice exercises or quiz. In order to gain a certificate of achievement, please complete the course lessons and practice drill during one session. Most users complete the course in 30-45 minutes.

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Lessons

Lesson #1: Vesicular - Normal

Vesicular breath sounds are soft and low-pitched with a rustling quality during inspiration and are even softer during expiration. These are the most commonly auscultated breath sounds, normally heard over most of the lung surface. They have an inspiration/expiratory ratio of 3 to 1 or I:E of 3:1.

Lesson #2: Crackles - Fine (Rales)

Fine crackles are characteristically heard as sounding like the popping of a wood fire or velcro being pulled apart. Early inspiratory and expiratory crackles frequently accompany chronic bronchitis, while late inspiratory crackles can indicate more serious medical conditions such as pneumonia, congestive heart failure (CHF), or atelectasis.

Lesson #3: Crackles - Coarse (Rales)

Coarse crackles are a loud and distinctive lung sound, often described as popping or bubbling. These intermittent sounds have a lower pitch than their fine counterparts and tend to linger longer in duration - try simulating the noise by rolling pieces of hair between your fingers near your ear!

Lesson #4: Wheeze

Wheezes are adventitious lung sounds that are continuous with a musical quality. Wheezes can be high or low-pitched. High-pitched wheezes may have an auscultation sound similar to squeaking. Lower pitched wheezes have a snoring or moaning quality. The proportion of the respiratory cycle occupied by the wheeze roughly corresponds to the degree of airway obstruction. Wheezes are caused by narrowing of the airways.

Lesson #5: Rhonchi - low-pitched Wheezes

Low-pitched wheezes (rhonchi) are continuous, both inspiratory and expiratory, low-pitched adventitious lung sounds that are similar to wheezes. They often have a snoring, gurgling or rattle-like quality. Rhonchi occur in the bronchi. Sounds defined as rhonchi are heard in the chest wall where bronchi occur, not over any alveoli. Rhonchi usually clear after coughing.

Lesson #6: Bronchial

Bronchial breath sounds are characterized by their hollow, tubular quality and higher pitch compared to vesicular. These noises can be heard during auscultation over the trachea area (considered normal) with a distinct pause between inspiration and expiration cycles of 1:3 ratio.

Lesson #7: Pleural Rubs

When auscultation is performed, pleural rubs can often be heard as creaking or grating sounds. These are produced by two inflamed surfaces rubbing against each other - similar to walking on fresh snow or the sound of leather-on-leather. Coughing does not affect these noises and they will usually change in intensity with respiration cycle (aimilarly increasing at inspiration, decreasing at expiration). A crucial distinction between them and pericardial friction rubs is that those continue even when patient holds their breath whilst a pleural rub stops immediately thereafter.

Lesson #8: Bronchovesicular 241

Bronchovesicular breath sounds are considered a hallmark of healthy lungs when auscultated in the mid-chest and posterior chest area between the scapula. They have an inspiratory to expiratory ratio (I:E) equal to 1:1. Bronchovesicular sounds are normal breathings heard in the mid-chest or posterior chest regions between the scapulae. The pitch is a combination of bronchial and vesicular components.

Authors and Reviewers

Heart sounds by Dr. Jonathan Keroes, MD and David Lieberman, Developer, Virtual Cardiac Patient.
Lung sounds by Diane Wrigley, PA
Respiratory cases: William French
David Lieberman, Audio Engineering
Heart sounds mentorship by W. Proctor Harvey, MD
Special thanks for the medical mentorship of Dr. Raymond Murphy
Reviewed by Dr. Barbara Erickson, PhD, RN, CCRN.
Last Update: 12/11/2022

Sources

Heart and Lung Sounds Reference Library Diane S. Wrigley
Publisher: PESI
Impact Patient Care: Key Physical Assessment Strategies and the Underlying Pathophysiology
Diane S Wrigley & Rosale Lobo
Practical Clinical Skills: Lung Sounds
Essential Lung Sounds Diane S. Wrigley, PA-C
Published by MedEdu LLC
PESI Faculty - Diane S Wrigley
Case Profiles in Respiratory Care 3rd Ed, 2019
William A.French
Published by Delmar Cengage
Essential Lung Sounds by William A. French
Published by Cengage Learning, 2011
Understanding Lung Sounds Steven Lehrer, MD
Clinical Heart Disease W Proctor Harvey, MD
Clinical Heart Disease
Laennec Publishing; 1st edition (January 1, 2009)