The headset with the probe in the heart cavity, enables the depolarisation in the heart and also the excitation spread at a voltage level of about 1-15 mV and with a frequency of 60-150 Hz to be made audible. The phono-cardiographic data produced e.g. by the heart muscle contraction, the heart valve movement and the blood flow or the surrounding structure, by the capacitor type microphone working using a bipolar probe. The data is converted to a voltage, made accessible at the headset. The signals can be optionally supplied, using a loudspeaker, a tape recorder or an oscillograph screen. A terminal for a commercial pacemaker battery can be used for the tape recorder or the oscillograph. An operating switch (1) is provided for the position mode and a switch (2) is provided for the stimulation mode. ADVANTAGE - Probe is positioned at optimum part and quickly changed over to stimulation mode. Easy for doctor to operate. With unipolar probe only electrical data is used.