Electronic stethoscope enables you to check symptoms in machin­ery, before they become a problem. Machine noise or vibrations are picked up by the stethoscope’s probe and a transducer converts the vibrations to an electronic signal. Start by pressing the probe against the machine body and adjust the sound level. When the probe is moved to a new position it should be easy to establish whether the probe is now nearer to or further away from the source of the noise. The condition of the machine can be checked based upon one’s own personal experience with the sound of the machinery or by comparing the sound to a reference signal of a healthy machine.