1. A method of estimating a slowness of a propagating wave in an earth formation; the method comprising: using a logging tool in a borehole to generate the propagating wave and acquire a plurality of signals indicative of the propagating wave; determining a slowness frequency coherence of the plurality of signals; determining a histogram of a slowness distribution from the slowness frequency coherence, wherein determining the histogram further comprises identifying peaks in a slowness-frequency coherence plot; estimating an edge of the histogram by matching statistics of a fitting function to statistics of the histogram, wherein matching the statistics further comprises using at least one of: (i) a centroid, (ii) a peak location, (iii) a second moment about a centroid, (iv) a second moment about the peak, (v) a skewness about a centroid, and (vi) a skewness about a peak; using the estimated edge of the histogram to estimate the slowness of the propagating wave; and recording the estimated slowness on a suitable medium.