The sounds produced by the flow of air through the respiratory system are referred to as respiratory sounds. Auscultation of the respiratory system through the lung fields with a stethoscope, as well as the spectrum features of lung sounds, can easily identify these. Normal breath sounds as well as “added” sounds like crackles, wheezes, pleural friction rubs, stertor, and stridor are included.
Auscultation of the inspiratory and expiratory phases of the breath cycle is frequently used to describe and classify the sounds, noting both the pitch (often defined as low, medium, or high) and intensity (soft, medium, loud, or very loud) of the sounds heard.
Abnormal Breath Sounds
| Name | Conditions |
| Wheeze or rhonchi | Asthma, chronic obstructive pulmonary disease, and foreign bodies all-cause constriction of the airways. |
| Stridor | croup, foreign body, laryngeal oedema, epiglottitis |
| Inspiratory gasp | pertussis (whooping cough) |
| Crackles | Pneumonia, pulmonary edema, TB, bronchitis, and heart failure |
| Pleural friction rub | lung lining inflammation, lung tumors |
| Hamman’s sign | pneumopericardium, pneumomediastinum |
Rales
In the lungs, there are small clicking, bubbling, or rattling sounds. When a person breathes in, they can be heard (inhales). They’re thought to happen when air enters closed air spaces. Rales can also be classified as moist, dry, fine, or coarse. This phrase is no longer widely used.
Ronchi
are rattling, harsh respiratory noises created by secretions in the bronchial airways. The noises are similar to snoring. The plural version of the singular word “rhonchus” is “rhonchi.” It has not been regarded proper terminology in thoracic auscultation since the mid-1990s, because significant confusion has been noted in the published literature, which confuses this with crepitations and wheezes, therefore the precise nature of this phrase is uncertain.
Stridor
When a person breathes, they make a wheeze-like sound. An obstruction of airflow in the windpipe (trachea) or the back of the neck is usually the cause.
Wheezing
Narrowed airways produce high-pitched sounds. They are most frequently heard when a person exhales (exhales). Without a stethoscope, you might sometimes hear wheezing and other unusual sounds.
Auscultation tests include pectoriloquy, egophony, and bronchophony. In whispered pectoriloquy, for example, the person being evaluated whispers a two-syllable number as the clinician listens through the lung fields. The whisper is not generally heard over the lungs, but if it is, it could indicate pulmonary consolidation. This is due to the fact that sound travels differently through denser (fluid or solid) media than it does through the air that should ordinarily be present in lung tissue. The person being investigated continuously speaks the English long-sound “E” (/i/) in egophony.
Crackles
Crackles are sporadic, short sounds that are most typically heard during inspiration. They are classed as fine (high pitched, very brief) or coarse (low pitched, extremely long) (low pitched, less brief). Crackling can be caused by two different methods. Small airways that had previously been occluded suddenly open. Close your wet lips lightly and open them rapidly to understand how this can happen. A ‘plop’ will be heard. Fine crackles form when this happens in the terminal bronchioles. Air bubbles via secretions, as in pulmonary edema and resolving pneumonia, according to another theory.
Egophony
Egophony (also aegophony) is an increase in the resonance of voice sounds detected when auscultating the lungs, which is frequently produced by compressed lung tissue due to pleural effusion, or consolidation due to infection (pneumonia) or malignancy.
The patient is requested to say ‘e’ while a stethoscope is placed on his chest. If it sounds like the letter ‘a,’ the patient has egophony. The sound has a ‘nasal quality to it. Simply close your nose with your fingers and pronounce ‘e’ to show this. You will hear the letter ‘a’.
It’s because high-frequency sounds are better transmitted across the faulty tissues stated above, whereas lower frequencies are filtered off.