The auditory modality offers great potential to interface designers in an increasingly busy world due to its unique advantages as a communication channel and the low storage and processing overheads offered by auditory display systems. However, the problem of increasing ambient acoustic noise presents a significant challenge to the sound designer. This thesis addresses this problem by applying theories from the field of acoustic ecology in the design of more efficient auditory interfaces. A review of the literature identified five specific concepts from this field which may have practical application in this regard. A case study was subsequently carried out to examine the human ear’s ability to determine the semantic context of short non-speech schizophonic sounds. In so doing, two sets of sounds were established based on high-level semantic discrimination which were in turn used in a controlled experiment to determine that the semantic context of a background sound plays only a minor role in the amount of attention it elicits in a competitive listening scenario. A further iteration of the experiment revealed that the level of auditory attention elicited by background sounds in the presence of a competing foreground music stimulus could be altered by manipulating frequency bandwidth. In addition, musical ability was studied as a factor and it was determined that it has only a minimal effect on one’s capacity to attend to multiple concurrent auditory tasks in a competitive listening scenario. The work contained in this thesis makes a number of contributions to the field: the identification of five key concepts from the field of acoustic ecology as being of practical use to sound designers in the design of more efficient auditory interfaces for use in busy real-world environments; the development of an experimental procedure using high-quality audio assets and equipment that allows for the examination of auditory attention in competitive listening scenarios across four performance measures; empirical data from two controlled experiments which presents evidence that high-level semantic processing plays only a minimal role in the allocation of auditory attention for background sounds in competitive listening scenarios, while low-level variables (specifically frequency bandwidth) can be manipulated to alter the amount of auditory attention elicited by background sounds in the presence of competing music stimuli; and correlation analysis data which presents evidence that musical ability has only a minimal effect on a listener’s capacity to attend to multiple concurrent auditory tasks in a competitive listening scenario.