Lung Sounds Lessons, Quizzes and Reference Guides

How to Listen to Lung Sounds

breath sounds auscultation

Learn lung sounds easily through a variety of ways! We offer courses, quizzes, reference guides, and repetition drills. Each of these resources will be discussed below. We suggest starting by reviewing the introductory content on this page, then taking the fundamentals of lung sounds course. Use the auscultation quizzes to evaluate your skills. The reference guide is helpful for fast look-up of lung sounds.

Personalized achievement certificates can be printed and scores are saved to the user's dashboard.

Lung and Breath Sounds

Auscultation of Lung Sounds

Auscultation of the lungs is an essential part of physical examinations. All fields of the chest wall should be examined, including the chest wall anterior, posterior, and flanks.

Fundamentals of Lung Sounds (free module and quiz)

This module provides an overview of lung sound characteristics followed by lessons on eight selected sounds. For each lung sound lesson, you will have access to text, a lung sound recording, and a dynamic waveform video.

This website provides additional auscultation courses, reference guides, and quizzes. Certificates of achievement are also available.

Lung Auscultation Locations

Auscultation of lungs sounds should be conducted over the anterior and posterior chest walls. See the associated illustration for these locations. Many stethoscopes have chestpieces with both bell and diaphragm. Typically, start with the diaphragm but switch to the bell to hear lower-pitched sounds.

The triangle of auscultation, found on the dorsum of the thorax, has a relatively thin layer of muscle. This makes it an ideal location for lung sound auscultation. You should ask the patient to cross their arms and lean forward.

Timing and Duration

During auscultation, note the sound's timing within the respiratory cycle such as inspiratory, expiratory or more specific terms such as early expiratory.


A lung sound's pitch (frequency) is an important characteristic. The observer should classify the sound or murmur's pitch as low, medium, or high. The stethoscope's bell can be helpful with low-pitched sounds, while the diaphragm is used for medium or high-pitched sounds.

Using Our Auscultation Lessons

Here we provide an example of lung sounds, a fine crackle.


Click the playback button on the torso to hear a short recording.

patient thorax when auscultating by stethoscope

patient position during auscultation
The patient was seated during auscultation.


A waveform is a plot of the lung sound's amplitude over time. Click the play button to view this waveform and hear the corresponding lung sound. This video will loop until paused.

Sound amplitude vs. time.

Start Fundamentals of Lung Sounds Course

Fundamental Lung Sounds


We have selected eight important lung sounds for this introductory auscultation course. Each lesson, described below, includes a textual description, audio recording, and a waveform video. Optionally, a quiz is available for testing your comprehension and listening skills.

Vesicular Lung Sounds

Vesicular lung sounds are the most common auscultated sounds, usually heard over most of the chest wall. These sounds are low to moderate sound intensity (volume) with a low-pitch (200-600 Hz) and with a rustling quality. During expiration, the sound intensity can diminish somewhat. The inspiration to expiration (I:E) ratio is typically 3 to 1.

Vesicular Lung Sounds - Lesson, Audio, Waveform

Bronchial Breath Sounds

Bronchial breath sounds are hollow, tubular sounds that are higher-pitched than vesicular sounds. They can be auscultated over the trachea and anteriorly along each side of the sternum, from the second to fourth intercostal spaces. Posteriorly, along the vertebral column from the third to sixth intercostal spaces.

The stethoscope's diaphragm is used for auscultating these lung sounds. There is a distinct pause in the sound between inspiration and expiration. I:E ratio is 1:3.

Bronchial Breath Sounds - Lesson, Audio, Waveform


Air flowing through a narrowed bronchus produces wheezes. Accordingly, these sounds will have their highest sound intensity when auscultating over or near the central airways.

Wheezes are adventitious lung sounds associated with secretions, obstructions, tumors, or airway compression. They are continuous sounds with a musical quality. High-pitched wheezes have a squeaking quality, while low-pitched wheezes are similar to snoring or moaning. The proportion of the respiratory cycle occupied by the wheeze roughly corresponds to the degree of airway obstruction.

Wheezes are also classified by when they appear in the respiratory cycle, e.g. inspiratory wheezing or a late expiratory wheeze. Moreover, information about the sound quality (monophonic or polyphonic) should be observed. These characteristics can be found in our Intermediate Lung Sounds module.

Wheeze - Lesson, Audio, Waveform


Rhonchi are continuous, low-pitched adventitious lung sounds caused by fluids or secretions in the large airways. They often have a snoring, gurgling, or rattle-like quality. They are heard primarily during expiration, but will appear during inspiration in some patients. Rhonchi will usually clear or alter in sound after coughing.

Having difficulty recognizing rhonchi vs rales? Use these pages: rhonchi lung sounds and rales lung sounds.

Rhonchi - Lesson, Audio, Waveform

Fine Crackles

Fine crackles are brief, discontinuous, popping, high-pitched breath sounds. These sounds are also similar to the sound of Velcro fasteners being pulled apart or cellophane being crumpled. Crackles can appear throughout the respiratory cycle.

Fine Crackles - Lesson, Audio, Waveform

Coarse Crackles

Coarse crackles are discontinuous, popping, or bubbling breath sounds. They are louder, lower in pitch, and of longer duration than fine crackles.

Coarse Crackles - Lesson, Audio, Waveform

Pleural Rubs

Pleural rubs are creaking or grating sounds. The sound is similar to leather against leather or walking on fresh snow on a cold day. Coughing will not alter the sound.

Pleural rubs are generated when two inflamed surfaces slide past one another, such as in pleurisy. During auscultation, try to identify a specific point on the chest wall where pleural rubs are loudest. These sounds occur with movement of the patient's chest and will stop when the patient holds her breath. They appear on inspiration and expiration. If the sound continue when the patient is holding her breath, it may be a pericardial friction rub.

Pleural Rubs - Lesson, Audio, Waveform


Stridor is created by air flowing through an upper airway that is narrowed or obstructed. It occurs in 10-20% of extubated patients. Stridor is a loud, high-pitched crowing breath sound heard during inspiration. Stridor may also occur throughout the respiratory cycle, particularly if the condition worsens. Often it is heard without a stethoscope. Causes of stridor are obstructions, pertussis, croup, epiglottis, aspirations.

Stridor - Lesson, Audio, Waveform

Authors and Sources

Authors and Reviewers


Lung Sounds Learning Resources

Free Teaching Accessrces

Learn about free online access to our teaching resources for lung sounds as well as heart sounds and EKG interpretation.

Free Teaching Access

Lung Sounds Reference Guide

This auscultation reference guide includes over twenty adventitious and normal breath sounds. The guide also includes listening tips and waveforms with a moving cursor.

Breath Sounds Guide

Fundamentals of Lung Sounds  

This module is an excellent starting point for learning lung sounds. This course provides an overview of lung auscultation, followed by 8 lessons.

Fundamentals of Lung Sounds

Lung Sounds Intermediate Course

This intermediate course covers advanced wheezes and crackles and introduces voiced sounds (bronchophony, egophony, whispered pectoriloquy).

Intermediate Lung Sounds

Lung Sounds Basics Course

This module is a supplemental course, largely replaced by our new Fundamentals of Lung Sounds. This basic course focuses on common vesicular, bronchial breath sounds and crackles and wheezes. The intermediate course covers advanced forms of wheezes and crackles and introduces voiced sounds (bronchophony, egophony, whispered pectoriloquy).

Basic Lung Sounds

Auscultation For Respiratory Care

For respiratory therapists, we have created a dedicated website for learning breath sounds as well as other essential clinical skills.

Lung Sounds in Respiratory Care

Auscultation Quizzes

We offer many graded quizzes, ranging from fundamentals to advanced topic. Quiz scores are saved to your personal dashboard.

Auscultation Quizzes
auscultation of the lungs

Auscultation Repetition Training

For some learners, auscultation repetition training is a useful complement to our courses. The repetition training modules include audio and a dynamic lung sound waveform for helping users learn each breath sound.

Repetition Training

Pulmonary Problem-Solving

We provide two courses, each with eight cases in pulmonary problem-solving that integrate clinical skills training with respiratory care. These cases require knowledge, reasoning and patient assessment skills.

Pulmonary Problems

lung sounds audio image

Authors and Reviewers


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