  Over the last ten years there has been a large increase in the number of
projects using sound to represent astronomical data and concepts. Motivation
for these projects includes the potential to enhance scientific discovery
within complex datasets, by utilising the inherent multi-dimensionality of
sound and the ability of our hearing to filter signals from noise. Other
motivations include creating engaging multi-sensory resources, for education
and public engagement, and making astronomy more accessible to people who are
blind or have low vision, promoting their participation in science and related
careers. We describe potential benefits of sound within these contexts and
provide an overview of the nearly 100 sound-based astronomy projects that we
identified. We discuss current limitations and challenges of the approaches
taken. Finally, we suggest future directions to help realise the full potential
of sound-based techniques in general and to widen their application within the
astronomy community.
