Computer-controlled scent output technologies have a history dating back nearly 50 years. However, it’s only in the last few years that such systems have become easy to use and readily available, fueled by the emphasis on multimedia technologies from the internet and dot.com boom and by the increasing prominence of fragrance in everyday life.
The key advantage of computercontrolled output, in whatever form it takes, is the ability to control when a scent is emitted. This seems so trivial as to be hardly worth mentioning, but is the key advantage that computer control brings to the application of aroma output. Some applications have an added advantage of allowing control over smell quality, specifying which aroma is output on cue. Perfumers have understood the role of time in their creations since time imme– morial — the progressive scents of top, middle and base notes in a perfume, diffusing over time. Being able to control onset time without direct action on behalf of the user is a key change in the way we think of scent.
This article explores this technology in three sections. First, I explore the technologies inherent in releasing scent on demand. Second, I look at various applica– tions that use computerized scent, starting with applications that use scent in conjunction with other media and continuing with a brief look at devices that release scent for its own sake. These applications and technologies are important precursors for the third section this paper: a novel application for computerized scent output: using scent to display abstract information. I explore both theory and application of such symbolic olfactory display, and point to some contexts for its use.