1. A method for processing an acoustic signal, the method comprising: preparing a first frequency-related representation of the acoustic signal over time; computing a two-dimensional transform of plural two-dimensional localized regions of the first frequency-related representation, each less than an entire frequency range of the first frequency related representation, to provide a two-dimensional compressed frequency-related representation with respect to each two dimensional localized region; identifying at least one pitch for each of the plural regions; and processing the pitch from the plural regions to provide multiple pitch estimates over time.