This document provides an overview of lung sounds and their characteristics. It begins by outlining proper auscultation technique and then describes the features of normal and abnormal breath sounds including vesicular, tracheal, bronchovesicular, bronchial, adventitious sounds like wheezes, crackles, and stridor. It notes the locations and causes of different lung sounds. In summary, it is a guide for identifying and interpreting various lung sounds through auscultation.

1. LUNG SOUNDS
Presented by-
Dr. Rohit Mehtani
R.M.O. Medicine
MYH
Guide-
Dr. Deepak Bansal
Assistant Professor
Dept. of Respiratory Medicine
MYH

2. Auscultation
• Ideally to be done in sitting position
• Auscultate symmetrically
• Note character and type of breath sounds
• Presence of any adventitious or added sounds
• Character of vocal resonance

5. Breath Sounds
• Normal
– Tracheal
– Bronchial
– Bronchovesicular
– Vesicular
• Abnormal
– Absent/Decreased
– Bronchial
• Adventitious
– Crackles (Rales)
– Wheeze
– Rhonchi
– Stridor
– Pleural Rub

6. Normal Breath Sounds
• Features to be noted in breath sounds-
– Intensity or loudness
– Quality or character
– Comparison of inspiratory and expiratory
elements of the sound
– Presence or absence of intermediate pause
between inspiration and expiration
– Other characters such as prolongation or jerky or
interrupted nature
– Presence of other sounds

7. Normal Breath Sounds
• Normal breath sounds generated by turbulent
airflow in upper airways, and larger airways of the
lungs ( 200 to 2000 Hz)
• As the sound is transmitted to the lungs, it gets
dampened, higher frequencies are lost and a softer,
lower pitched sound is heard (200 to 400 Hz).
• In the smaller airways, air flow is laminar and slower,
turbulence and sound cannot develop. Smaller
airways and alveoli are therefore a filter and not a
source of sound.
• Thus the term vesicular breath sounds should be
replaced with normal breath sounds.

8. Vesicular Breath Sounds
• Characters –
– Characteristic rustling or breezy
– Intensity of inspiration more than expiration
– Longer duration of inspiration
– Lower pitch of expiration
– No pause between inspiratory and expiratory sound
• Normally heard all over the chest except, over larynx, trachea
and lower cervical vertebrae, over and around the upper part
of sternum, 3rd
and 4th
dorsal vertebrae

9. Vesicular Breath Sounds
• Classically believed to be produced due to distension and
seperation of alveolar walls by in-rushing current of air.
• Others believe that laryngeal sound while travelling down
the bronchi into the alveoli, gets modified through addition
of sounds produced by passage of air from narrow terminal
bronchioles into the wide vestibules – producing rustling
quality.
• Actual duration of expiration is slightly longer than
inspiration, but the auditory component is much shorter as
elastic recoil of the distended lungs is maximal at onset of
expiration.

10. Tracheal Breath Sounds
• Characters –
– Blowing, hollow, or tubular quality
– Expiratory sound longer in duration than inspiration
– Distinct pause between inspiration and expiration
– Expiration higher in pitch and intensity
• Normally heard over the larynx, trachea and lower cervical
vertebrae
• Produced due to in an out movement of air through the
narrow aperture of glottis.
• Lower pitch of sound during inspiration is due to glottic
aperture being wider during inspiration.

11. Bronchovesicular Breath
Sounds
• Intermediate in character between vesicular and tracheal.
• Expiratory sound is louder, longer and higher in pitch than
inspiratory sound, and displays a hollow character
• Normally heard over and around upper part of the sternum,
near the third and fourth dorsal vertebrae
• Arises when normal air containing lung tissue is interposed
between a large bronchus and the chest wall, thus combining
characters of both vesicular and bronchial breath sounds.

12. Abnormal Breath Sounds
• Bronchial Breathing –
– High pitched inspiratory sound
– Pause between inspiration and expiration
– Very harsh and high-pitched expiratory sound
– Marked prolongation of expiration
– Blowing, tubular or hollow in character
– Similar to tracheal breathing, but is less intense and harsh
but of higher pitch.

13. Abnormal Breath Sounds
• Bronchial Breathing –
– Reliable sign of consolidation, but may be sometimes heard over
pulmonary collapse, particularly of the upper lobe.
– Normally, laryngotracheaal sound is modified by the lung tissue into
characteristic rustling vesicular character.
– When normally aerated lung tissue is replaced by consolidation,
glottic sound is conducted to chest wall without modification
through the solidified lung tissue.
– Size or capacity of the underlying air passage determines whether
the breath sound will be cavernous, tubular or amphoric.

14. • Cavernous or low-pitched bronchial breathing:-
– Hollow character
– s/o underlying cavity in the lung, open pneumothorax,
pulled trachea syndrome.
• Tubular or high-pitched bronchial breathing:-
– s/o consolidation of lung tissue, overlying small-sized
bronchial tubes.
– May be seen in lobar pneumonia, caseous pneumonia,
pulmonary infarction, atlelectasis or collapse of lung,
malignant disease of the lung.
Abnormal Breath Sounds

15. • d’espine sign – high-pitched tubular breathing heard over
thoracic spine due to transmission of tracheal breath sounds
through a mass in the middle or posterior mediastinum.
• Amphoric breathing:-
– High-pitched bronchial breathing with a distinctive echo-like
or metallic quality
– s/o large cavity in the lung with smooth walls, or a
pneumothorax communicating with a bronchus.
Abnormal Breath Sounds

16. • Broncho-vesicular breathing:-
– When consolidation of lung is incomplete, or patchy, the
bronchial sounds which emanate from underlying bronchial
tubes are modified during their transmission through
normally-aerated parenchyma, becoming bronchovesicular
in character.
– Causes are more or less similar to bronchial breathing.
Abnormal Breath Sounds

17. Adventitious Breath Sounds
• Stridor
– Inspiratory musical sound
– Loudest over trachea
– Suggests obstructed trachea or larynx
– Medical emergency requiring immediate
attention
– Associated condition
• inhaled foreign body

18. Adventitious Breath Sounds
•Wheeze:-
– Continuous, high pitched, musical sound, longer than
crackles
– Hissing quality, heard more with expiration, however, can be
heard on inspiration
– Produced when air flows through narrowed airways
– Wheeze is produced as air is forced past a point at which
opposing airway walls are just touching; these vibrate,
generating the wheeze.

19. Adventitious Breath Sounds
• MONOPHONIC WHEEZE
– FIXED MONOPHONIC WHEEZE –
• Single musical sound of constant pitch, timing and site heard on inspiration
• Result of air passing at high velocity through a localised narrowing of single
large airway, commonly from bronchial carcinoma.
– RANDOM MONOPHONIC WHEEZE –
• Random single notes of varying duration, timing and pitch, which may be
scattered and overlapping throughout inspiration and expiration.
• Signify diffuse airflow obstruction.
• Seen in bronchial asthma or bronchitis.

20. • POLYPHONIC WHEEZE
– EXPIRATORY POLYPHONIC WHEEZE –
• Expiratory musical sound containing several notes of different pitch
• Results from oscillation of several large bronchi simultaneously brought to
the point of closure by congestion of mucous lining, smooth muscle
contraction and thickening of mucus layer.
– SEQUENTIAL INSPIRATORY WHEEZE –
• Series of sequential but not overlapping inspiratory sounds or occasionally a
single sound, resulting from opening of airways which had become
abnormally apposed during previous expiration.
• Occur in deflated areas of lung and are heard in lung fibrosis, mainly fibrosing
alveolitis.
Adventitious Breath Sounds

21. Adventitious Breath Sounds
• Crackles (Rales)
– Interrupted, short, sharp non-musical sounds
– Heard more commonly with inspiration
– Crackles are miniature explosions that result from sudden
equalization of pressure when a closed airway seperating two
adjacent compartments of the lung, which contain gas under
widely different pressures, suddenly opens.
– Characteristic of pneumonia, pulmonary fibrosis, bronchiectasis
and pulmonary congestion.
• EARLY INSPIRATORY CRACKLES :-
– Seen in airflow obstruction
– Crackles in COPD and bronchiectasis are coarser, scanty and not
posture dependent.

22. • LATE INSPIRATORY CRACKLES:-
– Come from smaller airways
– Dependent on gravitational forces on the lung, and are best
heard at lung bases where the small airways close on expiration
– Seen in fibrosing alveolitis, pulmonary edema
– They are profuse, high pitched and modified by change in
posture
• EXPIRATORY CRACKLES:-
– Characteristic of severe airway obstruction
– Arise probably by re-opening of airways, temporarily closed by
the trapping mechanism as air is redistributed distal to larger
and more proximal airways narrowed by the trapping
mechanism during expiration.
– Independent of posture
Adventitious Breath Sounds

23. • COARSE CRACKLES :-
– Originating within large bronchial tubes
– Heard in consolidation, lung cavitation, abscess, pulmonary
congestion or edema and bronchiectasis.
• FINE CRACKLES :-
– “crackling” quality
– Localised, constant and accentuated by coughing
– Due to sudden seperation of sticky alveolar walls, at the end
of inspiration by the inrushing of air, and are indicative of
fluid exudation within the alveoli.
– Characteristic of first stage of pneumonia, early PTB,
collapse/atelactasis of lung, bronchitis or pulmonary edema.
• TRACHEAL RALES (DEATH RATTLE) :-
– Usually heard over the trachea or lungs in seriously ill patients
who are unable to cough out their respiratory secretions.

24. • Pleural Rub :-
– Due to inflammation of the pleura, as in acute dry pleurisy, the
two inflamed and roughened surfaces of the pleura rub against
each other
– Commonest site of pleural rub is lower part of axillae
– Characteristics:-
• Rubbing or creaking in quality
• Interrupted or jerky in nature
• Frequently loud in intensity
• Superficial in character
• Accentuated by increased pressure of the chest piece on the chest wall
• Audible during both phases of respiration
• Unaltered by coughing
• Confined to a small area of the chest
• Frequently palpable when coarse

25. VOCAL RESONANCE
• Auscultation of symmetrical areas of the two sides of
the patients bared chest is carried out while patient is
made to repeat phrases like “ninety nine”, “one one” or
“one two three”.
• Normally sounds are heard as weak, muffled and
indistinct rumbling, with individual syllables blurred and
indistinguishable.
• Louder in childhood and weaker in old age.

26. • INCREASED VR – noted in consolidation, infiltration of
lung tissue, small superficial cavity, partial atelectasis,
bronchiectasis, compensatory emphysema, over a
tumor/lymph node or adhesive band between bronchus
and chest wall.
• DECREASED VR – noted in partial obstruction of air
passage, hypertrophic emphysema, thickened pleura,
small pleural effusion, partial pneumothorax, edema of
chest wall, or malignant disease of the pleura.

27. • Absence of VR – may be seen in deaf-mutism, vocal
cord paralysis, large pleural effusion, severe
emphysema, pneumothorax, acute pulmonary edema
or absence of lung tissue.
• BRONCHOPHONY – when spoken voice sounds appear
unduly loud or intense, clear and sound close to the ear,
individual words or syllables however remaining
indistinguishable.
– Normally audible over larynx and trachea
– Pathological in lung consolidation, compressed lung tissue as
in pleural effusion (above the level of fluid) or intrathoracic
tumor, tuberculous or bronchiectasis lung cavity (surrounded
by consolidated lung tissue)

28. • AEGOPHONY – spoken voice sounds during
auscultation display a peculiar quivering, nasal
quality like “bleating of a goat”
– Due to pleural effusion (along the border of effusion),
over a pleural effusion overlying an area of lung
consolidation, over a cavity half filled with secretions.
– MODE OF PRODUCTION –
• Due to interposition of a thin layer of fluid between the lung
and chest wall, allowing transmission of overtones but
damping off lower fundamental tones
• Or due to partial compression of lung tissue underneath the
upper part of effusion, altering the normal relationship
between bronchi and lung parenchyma and thus reinforcing
high pitched nasal sounds.

29. WHISPERED VOICE SOUNDS
• Patient is asked to whisper phrases like “ninety nine”,
“one one” or “one two three” while chest is auscultated.
• Normally whispered sounds are heard very faintly over
certain areas of the chest, including main air passages,
7th
cervical spine, inner end of right 2nd
intercostal space
and in inter-scapular region.
• When heard over other areas or heard louder than
normal, then suggestive of patchy consolidation,
infiltration or distension of lung tissue.

30. • WHISPERING PECTORILOQUY
– When whispered voice is transmitted to the chest
wall with sufficient clarity, the individual syllables
being clearly distinguishable
– Suggestive of:-
• Fairly large cavity in the lung communicating with the
bronchus
• Massive or diffuse consolidation of lung tissue overlying or
adjacent to a bronchus
• Retracted or partially compressed lung tissue just above
the level of pleural effusion
• Obstruction of large bronchus by a tumor

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