Shaping sound like we do with light

Immersive technologies have received increased attention from the scientific community over the last two decades. According to previous research, the ‘sense of sound’ is the second most dominant sense after ‘vision.’ Taking this into consideration, advancements in immersive technologies, which were initially focused on visuals and graphics, have begun to pay more attention to sound delivery and perception. Currently, in the field of sound, headphones and loudspeakers are the two most common methods of delivering spatial sound. Studies exploring ‘directional sound’ and ‘localization of sound’ through loudspeakers are still limited in numbers. This thesis seeks to contribute to the field of immersive technologies by researching cutting-edge methods for delivering spatial sound at a location. This thesis begins with an introduction to the research questions (Chapter 1). It later compares the sound delivery methods and the environment utilized to deliver the sound by previous researchers. This provides information on the number of sound sources required to deliver sound in both a real and 3D environment around the user (Chapter 2). It then investigates sound localization with headphones in a web-based 3D environment. This part of the study, for the first time, is entirely conducted online (Chapter 3). This thesis looks into acoustic metamaterials (AMM) and how they can be used to create unique sound experiences using a loudspeaker (Chapter 4). Following the realisation of the potential to engineer the properties of audible sound using AMM, a new method for focusing sound at a distance originating from a loudspeaker is discussed (Chapter 5). A sound localization test was conducted using this new method (Chapter 6). All the experiments in this thesis are validated using a user study. In conclusion, this thesis advances research into the various spatial sound delivery techniques currently used for location-based sound delivery. A technique for manipulating the properties of sound using AMM is proposed. Based on AMM, a new method for sound localization is designed and tested.