A process for the elimination of thermal interferences in the infrared and video fire detection at an early stage in waste incineration plants, recycling facilities, warehouses and the like. The process is characterized by an additional noise and vibration analysis, by measuring the noise level of vehicles situated in the area to be detected or other thermal interference sources, with a distinction in measuring the noise level between day mode and night mode. The volume thresholds can thus be determined and be used as a threshold for determining whether a fire extinguishing sequence should be triggered.