A method for machining workpieces provides a machining electrode, which is guided at a specific distance to the workpiece. The acoustic correction filter is operable when the natural sound is muted by the mute attachment for filtering a signal derived from the vibration so as to create an artificial sound instead of the muted natural sound. According to the invention, at least a portion of the testing procedure composed of generating the test signal and determining the electric response of the device is performed using a functional unit, such as the signal generator or the analyser, integrated into the mobile station. The backscatter period can then be determined from the BP-number and the period of the internal pulses. This at least one determined variation metric is compared to a threshold for determining if the client station is moving. A heating device is disposed on a top side of the electric wood kiln adjacent to an outer side of the diversion fins and fluidly connected to the fan set.