Continuation of a broad-based research project is proposed where the general goal is to contribute to the development of quantitative models of information processing by the auditory system. The work involves experiments in relation to general statistical decision theory formulations for many binaural and monaural psychoacoustic experiments. Both the theoretical and experimental work derive from considerations of the functional form of the operations presumed to be carried out by the receiver, the nature of (necessary) assumptions regarding the structure and role of "internal" (biological) noise, neurophysiological interpretations, adaptive (learning) effects on choice of decision strategies by individual listeners, and nonsensory variables such as attention and memory.