hat is used to shape the spectrum of
        the signal when calculating artifact statistics. The output signal
        does not go through this filter. This is an optional way to tune the
        sensitivity of the algorithm to each frequency component of the
        signal. The default filter is less sensitive at alpha and beta
        frequencies and more sensitive at delta (blinks) and gamma (muscle)
        frequencies.
    axis : int
        Axis to filter on (default=-1, corresponding to samples).

 