1. A method for enhancing or extending a vision system of a human being, the method comprising providing a computer that is programmed: to represent at least one selected visual image region, having at least one color or hue associated with the region, in terms of at least one visual image parameter for the region, the at least one visual image parameter including at least one of: vertical coordinate range of the region; horizontal coordinate range of the region; center coordinates for the region; region brightness; dominant hue range or wavelength range of the region; change in a parameter value that characterizes the visual image, with respect to a reference parameter value; and time rate of change TRC in a parameter value that helps characterize the visual image region; to associate each of the visual image parameters with at least one of a first set of M 1 audio signal attributes (M 1 ≧1), the first set of attributes being drawn from signal carrier frequency, signal envelope frequency, carrier signal-envelope signal phase difference at a selected time, baseline amplitude, envelope signal amplitude relative to baseline amplitude, and signal time duration, and with a second set of at least one of M 2 audio signal attributes (M 2 ≧1), the second set of attributes being drawn from time rate of change of envelope frequency and time-rate-of-change of baseline amplitude; to allow the selected visual image region to be adjusted in at least one of a horizontal dimension and a vertical dimension so that the visual image region primarily includes a selected object whose apparent diameter is increasing with time or is decreasing with time; and to present the M 1 +M 2 audio signal attributes sequentially or simultaneously for the at least one selected region.