 | This articleneeds additional citations forverification. Please helpimprove this article byadding citations to reliable sources. Unsourced material may be challenged and removed. Find sources: "Respiratory sounds" – news ·newspapers ·books ·scholar ·JSTOR(May 2015) (Learn how and when to remove this message) |
| Respiratory sounds | |
|---|---|
| Other names | Breath sounds, lung sounds |
 | |
| Specialty | Respirology |
Respiratory sounds, also known aslung sounds orbreath sounds, are the specific sounds generated by the movement of air through therespiratory system.[1] These may be easily audible or identified throughauscultation of the respiratory system through thelung fields with astethoscope as well as from the spectral characteristics of lung sounds.[2] These include normal breath sounds and added sounds such ascrackles,wheezes,pleural friction rubs,stertor, andstridor.
Description and classification of the sounds usually involve auscultation of the inspiratory and expiratory phases of the breath cycle, noting both the pitch (typically described as low (≤200 Hz), medium or high (≥400 Hz)) and intensity (soft, medium, loud or very loud) of the sounds heard.[3]
Normal breath sounds are classified as vesicular, bronchovesicular, bronchial or tracheal based on the anatomical location of auscultation.[4][3] Normal breath sounds can also be identified by patterns of sound duration and the quality of the sound as described in the table below:[4]
| Name | Location where heard normally | Quality of sound | Sound duration | Example |
|---|---|---|---|---|
| tracheal | over thetrachea | very loud | expiratory sound duration is equivalent to inspiratory sound | |
| bronchial | over themanubrium | loud, high pitched | expiratory sound duration is longer than inspiratory sound | |
| bronchovesicular | anteriorly between the 1st and 2nd intercostal space; posteriorly in-between the scapulae | intermediate | expiratory sound duration is about equivalent to inspiratory sound | |
| vesicular | over most of both lungs | soft, low pitched | expiratory sound duration is shorter than inspiratory sound |
Common types of abnormal breath sounds include the following:[5]
| Name | Continuous/discontinuous | Frequency/pitch | Inspiratory/expiratory | Quality | Common Causes | Example |
|---|---|---|---|---|---|---|
| Wheeze orrhonchi | continuous | high (wheeze) or lower (rhonchi) | expiratory or inspiratory | whistling/sibilant | Caused by narrowing of airways, such as inasthma,chronic obstructive pulmonary disease, foreign body. |  Problems playing this file? Seemedia help. |
| Stridor | continuous | high | inspiratory, expiratory, or both[6] | whistling/sibilant | epiglottitis, foreign body, laryngealedema,croup | Problems playing this file? Seemedia help. |
| Inspiratory gasp | continuous | high | inspiratory | whoop | pertussis (whooping cough) | see New England Journal of Medicine,Classic Whooping Cough sound file, Supplement to the N Engl J Med 2004; 350:2023-2026 |
| Crackles (rales) | continuous | high (fine) or low (coarse) | inspiratory | cracking/clicking/rattling[7] | pneumonia, pulmonary edema, tuberculosis, bronchitis, heart failure | Problems playing this file? Seemedia help. |
| Pleural friction rub | discontinuous | low | inspiratory and expiratory | many repeated rhythmic sounds | inflammation of lung linings, lung tumors | not available |
| Hamman's sign (or Mediastinal crunch) | discontinuous | neither (heartbeat) | crunching, rasping | pneumomediastinum,pneumopericardium | not available | |
| Grunting | Continuous | low | expiratory | snoring | surfactant deficiency, pneumonia, cardiac abnormalities[8] |
Pectoriloquy,egophony andbronchophony are tests ofauscultation that utilize the phenomenon ofvocal resonance.[3] Clinicians can utilize these tests during a physical exam to screen for pathological lung disease. For example, inwhispered pectoriloquy, the person being examined whispers a two syllable number as the clinician listens over thelung fields. The whisper is not normally heard over the lungs, but if heard may be indicative ofpulmonary consolidation in that area. This is because sound travels differently through denser (fluid or solid) media than the air that should normally be predominant in lung tissue. In egophony, the person being examined continually speaks the English long-sound "E" (/i/). The lungs are usually air filled, but if there is an abnormal solid component due to infection, fluid, or tumor, the higher frequencies of the "E" sound will be diminished. This changes the sound produced, from a long "E" sound to a long "A" sound (/eɪ/).
In 1957, Robertson and Coope proposed the two main categories of adventitious (added) lung sounds. Those categories were "Continuous" and "Interrupted" (or non-continuous).[12] In 1976, the International Lung Sound Association simplified the sub-categories as follows:
Several sources will also refer to "medium" crackles, as a crackling sound that seems to fall between the coarse and fine crackles. Crackles are defined as discrete sounds that last less than 250 ms, while the continuous sounds (rhonchi and wheezes) last approximately 250 ms. Rhonchi are usually caused by a stricture or blockage in the upper airway. These are different fromstridor.
{{cite journal}}: CS1 maint: DOI inactive as of November 2024 (link)Mansy, H. A.; Royston, T. J.; Balk, R. A.; Sandler, R. H. (2002). "Pneumothorax detection using computerised analysis of breath sounds".Medical & Biological Engineering & Computing.40 (5):526–532.doi:10.1007/BF02345450.PMID 12452412.S2CID 7413897.