Adventitious Breath Sounds

Adventitious Breath Sounds

Welcome to our website's adventitious breath sounds page. On this page we provide a definition and examples of several types of adventitious breath sounds. There is also a link to the free training courses available on this site.

adventitious breath sounds illustration

What Are Adventitious Breath Sounds?

Adventitious breath sounds are abnormal, extra sounds that are heard when auscultating a patient. These sounds include abnormal lung sounds such as fine and coarse crackles (crackles are also called rales), wheezes (sometimes called rhonchi), pleural rubs and stridor. Adventitious breath sounds are important clues used for diagnosing numerous cardiac and pulmonary conditions. These sounds and corresponding conditions are described in our lung sounds courses.

Crackles and Wheezes Adventitious Breath Sounds


Crackles are discontinuous, brief, popping sounds. Similar to the sound of a hook and loop fastener being pulled apart.

Wheezes are continuous, musical sounds, high or low pitched. Usually more pronounced on expiration.

Pleural Rubs and Stridor Adventitious Breath Sounds

Pleural Rubs

Plural rubs are creaking or grating sounds that have been described as being similar to walking on fresh snow.

A loud, high-pitched sound heard during inspiration but may also occur throughout the respiratory cycle.

Adventitious Breath Sounds Audio and Listening Tips

Our auscultation guide provides information and examples of adventitious lung sounds. The guide pages provide waveforms with a moving cursor that is synchronized to the audio recording. In addition, listening tips are available.
Lung Sounds Reference Guide

Adventitious Breath Sound Lesson

Our short courses on lung sounds cover many adventitious sounds.
Basics of Lung Sounds
Intermediate Lung Sounds