Phonocardiogram (below) and electrocardiogram in the third lead (top) healthy man: I and II of the first and second tone.

Ponografia is a graphical method of registration of the sound waves. In medicine used phonocardiography is a method of registration of the sound that is created in the heart of its activities, with the help of the device - phonocardiography. The latter consists of a microphone, perceiving sound waves, amplifier and recording devices. Microphone alternately put in those points on the chest, where usually listen heart auscultation (see the Heart). So write curve - phonocardiogram (FCG). Simultaneously with FCG record electrocardiogram. In norm on FCG (Fig) note oscillations corresponding to the first and the second with the colors of the heartwhich have a certain amplitude and duration. The first tone coincides with the micro ECG, the second appears after the end of the tooth So
Phonocardiography has a significant help in the diagnosis of heart disease, especially his vices. It allows to register separately the sound vibrations of low and high frequencies, which are poorly captured auscultation of the heart. Using FCG is possible to identify different tone changes, the appearance of surplus tones, to clarify the nature of cardiac murmurs.