It's receiver. I believe it came about from operators looking radar receivers and fiddling with the gain. Low gain, nothing is a target, high gain everything is a target.
it’s the first way we began thinking about ROC. My understanding agrees with the GP: this was a norbert wiener- era application of binary classifiers for “is there a submarine there, or not?” tasks.
ROC was next adopted by the psychophysics community. “Did you hear that tone, or not” is a pretty easy extension of the original task...and involved many of the same researchers after the war was over.