Assessments of bat activity from acoustic recordings of calls and call sequences lack consistency in collection and interpretation. Making cross study comparisons, especially legacy studies, unreliable. This study seeks to provide evidence for standardizing this process and develop transformation equations to correct the differences among sampling methods. To compare the different acoustic methods, we use thermography to establish a reference standard of actual bat activity within the sample area. The sample area encompasses the effective volume from the acoustic detectors. Two infrared cameras with overlapping fields of view monitored this sample area during audio recordings. This sample area was divided into stations every ten meters along 5 transects every 22.5 degrees in order to create a control set of data with prerecorded bat calls that allowed us to test the effects of each survey’s conditions on known sonograms. Counts determined from thermography will then be compared to experimental groups made from the original recordings, divided by different definitions of a bat pass. The results of this study will determine the validity of the definition of a bat pass provided by the protocol from the North American Bat monitoring program (NABat).