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Intermediate Lung Sounds

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In this intermediate course, expand your auscultation proficiency with breath sounds like wheezes, crackles, and stridor. Further deepen your understanding by hearing voiced lung sounds in normal and abnormal scenarios. Follow along with the audio examples which are accompanied by text descriptions alongside dynamic waveforms for further comprehension.

Using this course

This course offers an in-depth examination of lung abnormalities, providing students with descriptive texts and diagrams to indicate the optimal location for stethoscope chestpiece placement. Audio recordings combined with waveforms provide a comprehensive visual aid that will help learners gain further insight into understanding these unique sounds.

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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Lesson #1: Vesicular - Diminished

Diminished vesicular sounds are of lower intensity and are less full or robust than vesicular sounds. These sounds can occur in patients who move a lowered volume of air, such as in frail, elderly patients or shallow breathing patients. They are also heard with obese or highly muscular patients, where tissue mass impedes sound. They exhibit a normal inspiration to expiration ratio of 3 to 1, or 4 to 1.

Lesson #2: Bronchophony - Healthy

Have the patient repeat '99' while you auscultate their chest walls. With healthy lungs, this whispered phrase will not be audible due to impeded sound transmission. Be sure to compare your findings with an auditory example in our Bronchophony - Abnormal lesson!

Lesson #3: Bronchophony - Abnormal

Ask the patient to say '99' several times while auscultating the chest walls. Over consolidated areas '99' is understandable. This is because acoustic filtering is reduced in consolidated lung tissue, which allows better sound transmission. Compare this breath sound to the recording in the Bronchophony - Healthy lesson.

Lesson #4: Egophony - e

Egophony is a distinct sound often likened to the bleating of goats. It can be identified by asking patients to repeatedly say "Eeee" and listening attentively for higher intensity over abnormal lung areas. In comparison, healthy regions typically produce clear pronunciation with no particular nasal tone, as demonstrated on the Egophony - a lesson.

Lesson #5: Egophony - a

Egophony is a voiced sound with a nasal quality, often described to be like a goat's bleating. Egophony has higher intensity over abnormal lung areas. Ask the patient to say 'Eeee' several times. Auscultate the chest walls. Over consolidated lung areas, the sound is heard as an 'A' (aaay). Compare this sound to the recording in the Egophony - e lesson.

Lesson #6: Whispered Pectoriloquy - Healthy

To test for whispered pectoriloquy, have your patient whisper '1-2-3' a few times. If the voice's high frequencies seem dampened, that would suggest an abnormal lung area - compare it to what is heard in our lesson on Whispered Pectoriloquy - Abnormal.

Lesson #7: Whispered Pectoriloquy - Abnormal

Voice high frequencies are more readily transmitted to the chest wall in abnormal lungs as compared to normal lungs. Ask the patient to whisper '1-2-3' several times while auscultating across the chest walls. The lung area is abnormal if the '1-2-3' sound is understood. This is the abnormal '1-2-3'. Compare this sound to the recording found in the Whispered Pectoriloquy - Normal lesson.

Lesson #8: Wheeze - Expiratory

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 #9: Wheeze - Monophonic

Monophonic wheezes are loud, continuous sounds occurring in inspiration, expiration or throughout the respiratory cycle. The constant pitch of these sounds creates a musical tone. The tone is lower in pitch compared to other adventitious breath sounds. The single tone suggests the narrowing of a larger airway. These lung sounds are heard over anterior, posterior and lateral chest walls. These sounds can be more intense over lung areas affected by partial obstructions.

Lesson #10: Wheeze - Polyphonic

Polyphonic wheezes are loud, musical and continuous. These breath sounds occur in expiration and inspiration and are heard over anterior, posterior and lateral chest walls. These sounds are associated with COPD and more severe asthma.

Lesson #11: Crackles - Early Inspiratory (Rales)

Early inspiratory crackles (rales), as suggested by the title, begin and end during the early part of inspiration. The pitch is lower than late inspiratory crackles. A patient's cough may decrease or clear these lung sounds. Early inspiratory crackles suggest decreased FEV1 capacity and are characteristic of COPD.

Lesson #12: Crackles - Late Inspiratory (Rales)

Late inspiratory crackles (rales) begin in late inspiration and increase in intensity. They are normally higher-pitched and can vary in loudness. These adventitious breath sounds resemble the noise made when hook and loop fasteners are being separated. These sounds are heard over posterior bases of the lungs. They may clear with changes in posture or several deep breaths. They do not clear with coughing.

Lesson #13: Stridor

Stridor is caused by upper airway narrowing or obstruction. It is often heard without a stethoscope. It occurs in 10-20% of extubated patients. Stridor is a loud, high-pitched crowing breath sound heard during inspiration but may also occur throughout the respiratory cycle most notably as a patient worsens. In children, stridor may become louder in the supine position. Causes of stridor are pertussis, croup, epiglottis, aspirations.

Authors and Reviewers


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