A method for determining if one audio signal is derived from another audio signal or if two audio signals are derived from the same audio signal compares reduced-information characterizations of said audio signals, wherein said characterizations are based on auditory scene analysis. The system helps the user select tasks to be performed during the study by reference to a historical database of tasks previously associated with similar protocols. The invention is relied on color change, due to temporally photo-bleaching of a colored lens care solution, to indicate the readiness of disinfection and cleaning of contact lenses. Also provided is a method for manufacturing the housing.