  Since Siri's release in 2011 there have been a growing number of AI-driven
domestic voice assistants that are increasingly being integrated into devices
such as smartphones and TVs. But as their presence has expanded, a range of
ethical concerns has been identified around the use of voice assistants, such
as the privacy implications of having devices that are always listening and the
ways that these devices are integrated into the existing social order of the
home. This has created a burgeoning area of research across a range of fields
including computer science, social science, and psychology. This paper takes
stock of the foundations and frontiers of this work through a systematic
literature review of 117 papers on ethical concerns with voice assistants. In
addition to analysis of nine specific areas of concern, the review measures the
distribution of methods and participant demographics across the literature. We
show how some concerns, such as privacy, are operationalized to a much greater
extent than others like accessibility, and how study participants are
overwhelmingly drawn from a small handful of Western nations. In so doing we
hope to provide an outline of the rich tapestry of work around these concerns
and highlight areas where current research efforts are lacking.
