In some embodiments, methods, apparatus, and systems may operate to launch acoustic waves along a first acoustic path length from an acoustic transducer. The apparatus receives a reflected signal in response to each acoustic wave, each reflected signal including at least one echo. The reflected signal is decomposed, using a time-frequency decomposition method with basis functions, into a wavelet associated with each echo. Parameters describing each associated wavelet are determined and a borehole evaluation or pipeline inspection is performed based on the parameters.