Auscultation of lung sounds and murmurs

R. Beňačka, MD, PhD


Aim: To gain basic practical experiences and theoretical knowledge in auscultation of lung sounds and murmurs in preclinical training.


Methods: 1) For training of auscultations skills the model simulator is used  (The Life / Form Auscultation Trainer and Smartscope simulator. The system is equipped with a the torso of the chest of an adult man figurine, wireless programmable unite containing with a set of pre-programmable respiratory and cardiac sound phenomena and special stethoscope with sound generator producing sounds in a stethoscope bell. When the bell is being moved over the particular auscultatory points, the place – specific sounds are heard. A map showing these typical auscultatory sites for both respiratory and cardiac sounds is also available with the simulator and is of beneficial use. The points are also noted by colors spots on the surface of figurine in order to help in navigation. If the stethoscope bell is placed outside the usual auscultation points no sound can be heard. 2) Students perform listening in within groups one after another. In the beginning the auscultation for one or more sounds is demonstrated by the teacher. After setting of the sound in program unite teacher uses stethoscope to hear the sounds  when mover over specific points on figurine while students can hear the sounds through the speaker. After then, each trial being separated by sufficient disinfection of the olives in the stethoscope, students can train listening of selected phenomena themselves,


Life/Form Auscultation Trainer and Smartscope. (adult) (adult) Nasco (Fort Atkinson, Wisconsin): Lung: 5, anterior, 10 posterior, and 2 midaxillary locations. Heart: 6 anterior sites. Remote controller selects heart and lung sounds. Smartscope plays sounds through in-stelhoscope transceiver. Placement of stethoscope on chest activates transponder playback of audio files. Dual headsets and

remote speaker playback options.


Lung auscultation simulator


A) Basic breathing sounds 

1 Normal breathing - sample

2 Vesicular breathing

3 Bronchovesicular breathing

4 Bronchial breathing

5 Tracheal breathing





(B) Adventitios lung sounds

6 Wheezes (polyphasic)

7 Wheezes (monophonic

8 Rhonchi

9 Crackes (rales) fine

10 Cracles (rales) coarse

11 Stridor

12 Pleural friction rig



Additional sound samples

13 Cavernous breathing

14 Egophonia

15 Pectoriloquia

16 Pulmonary edema - sound

Technology for Enhancing Chest Auscultation in Clinical Simulation |  Respiratory Care




Breath sounds are generated by the air-flow passing through the different parts of the lower airways during inspiratory - expiratory cycle and the effect of these structures on an moving air. The pattern of normal breath sounds is a result of a given physical properties of lung matter the sound is conducted though from the place it is created towards the auscultation point. The same phenomena  can be heard a bid differently from different places. Sound phenomena related to breathing can subdivided into 2 broad categories: normal lung sounds and abnormal lung sounds (murmurs).


Normal breathing sounds refer to how the normal typical eupnoeic breathing cycle composed of inspiration and expiration can be heard from different locations over the chest, provided the breathing is performed in a normal rate and appropriate intensity (deeper than quiet rest breathing). Sounds are physiologically classified  as vesicular, bronchial,  bronchovesicular  and tracheal sounds. According to their location, breath sounds are described by:

      duration (how long the sound lasts),

      intensity (how loud the sound is),

      pitch (how high or low the sound is),

      timing (when the sound occurs in the respiratory cycle).


Normal findings on auscultation include:

1) Soft, breezy, low-pitched vesicular breath sounds over most of the peripheral lung fields

2) Loud, high-pitched bronchial breath sounds over the trachea

3) Medium pitched bronchovesicular sounds over the mainstream bronchi, between the scapulae, and below the clavicl


Normal breathing sounds



Vesicular sounds are soft, blowing or rustling sounds normally heard throughout most of the lung fields. Vesicular sounds are normally heard throughout inspiration, continue without pause through expiration, and then fade away about one third of the way through expiration


Bronchial sounds are present over the large airways in the anterior chest near the 2nd and 3rd intercostal spaces, Bronchial sounds are high in pitch, louder and more tubular and hollow-sounding than vesicular sounds, but not as harsh as tracheal breath sounds. Expiratory sounds last longer than inspiratory sounds or duration  is the same. Intensity of inspiration and expiration is the same. There is a short gap between inspiration and expiration.


Bronchovesicular sounds are heard in the posterior chest between the scapulae and in the center part of the anterior chest. Bronchovesicular sounds are softer than bronchial sounds, but have a tubular quality. Bronchovesicular sounds are about equal during inspiration and expiration; differences in pitch and intensity are often more easily detected during expiration.


Tracheal breath sounds are heard over the trachea. These sounds are harsh and sound like air is being blown through a pipe.

In a normal air-filled lung, vesicular sounds are heard over most of the lung fields, bronchovesicular sounds are heard between the 1st and 2nd interspaces on the anterior chest, bronchial sounds are heard over the body of the sternum, and tracheal sounds are heard over the trachea.





Weezing This is the sound of wheezing when auscultating breath or lung sounds. It can be heard when there is an airway obstruction such as when you listen to a patient with mild to moderate asthma during an exacerbation. Wheeze is mainly expiratory and occurs during both phases..


Fine Crackles (aka Rales) are high pitched sounds mostly heard in the lower lung bases. This can be abnormal findings on physical exam suggestive of things like congestive heart failure, pneumonia or atelectasis.


Coarse Crackles are low pitched lungs sounds heard in pathologies such as chronic bronchitis, bronchiectasis, pneumonia, and severe pulmonary edema. Compared to fine crackles, they are often louder, longer in duration and lower in pitch.


Squawks short inspiratory wheezes (200 ms; 200 - 300 Hz) in late inspiration often preceded by late inspiratory crackles. Squawks are found in: pulmonary fibrosis, pneumonitis, pneumonia, allergic alveolitis and bronchiolitis oblite-rans. They are produced by the oscillations of peripheral airways in deflated lung zones opened in late inspiration.


Pleural rub is nonmusical, short,. biphasic (inspiro-expiratory)  explosive sound (grating, rubbing, creaky, or leathery). It occurs due to inflamed pleural surface rubbing each other during breathing.


Stridor is loud, high-pitched, mainly inspiratory,.musical sound produced by upper respiratory tract obstruction. It is different from wheezing:  It is louder over the neck than chest wall. In expiration, it is biphasic. Stridor is caused by the turbulent flow passing through a narrowed segment of the upper respiratory tract.







Note:  There are myriads of available text or audio-visual  internet resources to increase the knowledge output.

Below is a recommened samples of useful sources.


Recommended audiovisual internet resources – Respiration


1.Breathing (simple illustrated edition) Armando Hasudungan

Mechanism of Breathing

Control Of Respiration

Respiratory gas exchange:

Understanding spirometry:

Lung Function - Lung Volumes and Capacities:

Oxygen - Haemoglobin Dissociation Curve:

Respiratory System Physiology - Ventilation and Perfusion (V:Q Ratio)


2. Auscultation if lungs

 Lung Sounds Collection – EMTprep


Respiratory sounds:


A) Basic breathing souds

Vesicular Breath Sounds:

Bronchovesicular Breath sounds

Bronchial Breath Sounds


B) Additional sounds

Wheezing (expiratory):


Fine Crackles (Rales) :

Coarse Crackles (Rales):


Sounds of Croup (Laryngotracheitis):