Auscultation

Auscultation (listening) - one of the basic methods of the clinical examination of the patient, which consists in listening to the sound of the phenomena that sprang up spontaneously in the body.
In practice carried out as the immediate or direct, auscultation (listening directly to the ear, applied to the body of the patient)and indirect auscultation using a stethoscope, the phonendoscope. With the direct auscultation audibility much better than when using a stethoscope, as we listen to the noises are not distorted; for example, weak bronchial breath, see diastolic murmur in aortic insufficiency sometimes detectable only by this way.
stethoscope and stetophonendoscopeFor indirect auscultation use solid stethoscopes of wood, plastic or flexible binaural stethoscopes, consisting of a funnel and two rubber tubes, stetophonendoscope, the phonendoscope (Fig. 1-3). Stethoscope is a complete speaker system; the air in it - the main conductor of sound, especially in flexible stethoscope; in the case of a message to the outside air or the closure of the lumen of the tube auscultation becomes almost impossible. Given the emphasis solid stethoscope in the ear of some importance is conducting sound of the bones of the skull. Auscultation through a stethoscope noises more or less distorted due to resonance, but provides a better delimitation of noises of different origin on a small area (for example, auscultation of the heart); perceived noise clearly.
Auscultation is of exceptional importance in the study of lung, heart and blood vessels, blood pressure measurements on Korotkova, identifying intestinal noise.

Auscultation (lat. auscultatio - listening is one of the main methods of clinical research, which consists in listening to the sound of the phenomena that sprang up spontaneously in the body.
Auscultation studied and introduced into medical practice the Laennec (K. Laennec). The nature of acoustic phenomena detected by auscultation, depends on the physical properties (density, pressure, mass) oscillating bodies, anatomical structure and intensity of organ functions. Fluctuations tissue structures arise in the act of respiration, heartbeat, the movements of the stomach and intestines; part fluctuations reaches the surface of the body (skin). Each point on the surface of the body is the source of the sound waves that propagate in all directions; as the distance from the source of the sound wave energy is distributed to all large volumes of air, so quickly decreases the amplitude of oscillations, and the sound is so loud that it is not perceived by the ear, not in contact with the body. The principal value of the stethoscope, as the direct attachment of the ear to the body, is that it prevents weakening of sound from the dissipation of energy.
All occurring in the body sounds are noise, i.e. a mixture of sounds of different frequencies. The ear is most sensitive to sounds around 2000 Hz. With decreasing frequency sensitivity decreases sharply, so with the same intensity high frequency sounds seem to be louder than the sound of low frequencies. Ear easier distinguishes between changes in the frequency or pitch than in sound intensity. The faint sound after a strong perceived with difficulty; in addition, in a mixture of sounds of different frequencies strong vibration one frequency masking weaker oscillations other frequencies.
Sounds perceived auscultation of the lungs and heart, by frequency do not exceed 1000 Hz. Ear picks up only about 10% of the vibrations caused by heart (normal heart is the source of oscillations with a frequency of 5 to 800 1 sec.), because of the volatility too low frequencies (below 20), i.e. below the threshold of perception (infrazvuky)and some low intensity. However, the value auscultation is very high. Phonocardiographic studies have confirmed explain almost all sound phenomena of the heart (the colours, noise), established clinical A. (see Ponografia).
In practice used as the immediate or direct, A. and indirect using a stethoscope, the phonendoscope and others With direct auscultation audibility much better than when using a stethoscope, as we listen to the noises are perceived directly by the ear and not distorted. For example, weak bronchial breath, diastolic murmur in aortic insufficiency sometimes recovered only in this way. B. N. Samples proposed an original method of direct A. to recognize incremental tone when gallop rhythm. The necessary condition of this method a is dense pressing ear to the heart, this forms a closed air cavity and the first heart sound and gallop rhythm acquire the character of the ringing sound due to the boost from the heart on the chest, as gallop rhythm is a tone-push.
For indirect auscultation use solid stethoscopes of wood, plastic or flexible binaural stethoscopes, consisting of a funnel and two rubber tubes, stetophonendoscope and phonendoscopes.
Stethoscope is a closed acoustic system, and the air it is the primary medium of sound, especially in flexible stethoscope; in the case of a message to the outside air or the closure of the lumen of the tube auscultation becomes almost impossible. Given the emphasis solid stethoscope to the ear of some importance is conducting sound of the bones of the skull. In A. through a stethoscope noises more or less distorted due to resonance, but provides better localization and delimitation of noises of different origin on a small area (for example, if A. the heart); perceived noise clearly. Necessary condition of successful A. is the silence in the house or office.
Auscultation is an indispensable method of clinical research. It is of exceptional importance in the study of lung, heart and blood vessels, blood pressure measurements on Korotkova, identifying intestinal noise, the study of the joints, etc.