  Speech interfaces are growing in popularity. Through a review of 68 research
papers this work maps the trends, themes, findings and methods of empirical
research on speech interfaces in HCI. We find that most studies are
usability/theory-focused or explore wider system experiences, evaluating Wizard
of Oz, prototypes, or developed systems by using self-report questionnaires to
measure concepts like usability and user attitudes. A thematic analysis of the
research found that speech HCI work focuses on nine key topics: system speech
production, modality comparison, user speech production, assistive technology
\& accessibility, design insight, experiences with interactive voice response
(IVR) systems, using speech technology for development, people's experiences
with intelligent personal assistants (IPAs) and how user memory affects speech
interface interaction. From these insights we identify gaps and challenges in
speech research, notably the need to develop theories of speech interface
interaction, grow critical mass in this domain, increase design work, and
expand research from single to multiple user interaction contexts so as to
reflect current use contexts. We also highlight the need to improve measure
reliability, validity and consistency, in the wild deployment and reduce
barriers to building fully functional speech interfaces for research.
