The predicted workflow is like this. First you set Stats.Recursive to True and specify for example Stats.Averaging := avLinear. Then you compute multiple frequency spectrums by calling Update or Pull method. Once sufficient number of averages has been obtained (Stats.Averaged), call UpdateSpectrumStats method to compute averaged frequency spectrum, optional standard deviation and confidence intervals. 

If Stats.Recursive was True, the averaged spectrum, standard deviation and confidence intervals were evaluated for each newly computed frequency spectrum. 

Consequently if the data is processed off-line, it makes more sense to set Stats.Recursive to false, and if live data is being observed like signal comming from the microphone, it makes more sense, to leave the Stats.Recursive property set to True. The speed of processing can be as much as 10x lower, if Recursive is True, standard deviation is required and confidence intervals are computed, because all the stats is evaluated for every iteration.

TSpectrumAnalyzer Methods