In an exemplary implementation of a method and system for determining the direction of fluid flow, one or more sound transducers are positioned in proximity to a conduit, each such sound transducer generating a signal representative of a selected characteristic of acoustic waves emanating from the conduit. Such signals are collected and analyzed to determine a threshold value for the selected characteristic (e.g., frequency) indicative of a change in the direction of fluid flow through the conduit. Based on whether subsequent measurements of the selected characteristic (e.g., frequency) are above or below the threshold value, the direction of fluid flow can be predicted and/or a change in the operational state of a component associated with the conduit can be identified.