A special tool for inspecting wound canals has been developed, consisting of a flexible probe for individual use and a handle-holder with a microphone capsule, the membrane of which is directly connected to the probe and reacts to mechanical contact with an obstacle, and the capsule itself is directly connected to the oscilloscope through a signal amplifier, which has spectral signal processing chains. Functional conditioning of the controlled signals from the shape and type of the foreign object in the wound channel was revealed. The expediency of using the frequency-amplitude characteristic of noise emission as a controlled parameter has been proven. Thus, the existence of a functional conditioning of the width of the spectrum of the noise emission signal at the time of mechanical contact with a foreign object in the wound, its shape and type is shown; it was determined that the use of an oscilloscope with a spectral analysis channel allows fairly accurate identification of a nonradiocontrast foreign object in a wound.