Using olfactory media to enhance traditional multimedia content opens up novel opportunities for user interactions. Whilst the influence of olfaction on user experience in mulsemedia (multiple sensorial media) environments has been previously studied, the impact of the fundamental dimensions of scent intensity and valence (odor hedonic dimension or pleasantness) have been largely unexplored. This is precisely what we target in this paper, which reports the results of an empirical investigation examining how scent intensity and valence impact mulsemedia Quality of Experience (QoE). Accordingly, 54 participants were exposed to different odor valences and scent intensity levels when viewing three short multimedia clips. In particular, we examine both subjective (self-reported) as well as objective QoE metrics, as evidenced by user heart rates and eye gaze patterns. Results show that whilst eye gaze patterns are largely unaffected by the experimental conditions, valence does have a statistically significant impact upon user heart rates, as does intensity for two of the three clips employed in our study. In terms of subjective QoE, results indicate that hedonic valence impacts on the sense of reality and enjoyment; however varying odor intensity levels do not seem to differentially impact on user experience, bringing into question the need for strong scent intensities.

Recently, the concept of adding multisensory media components to complement and extend user Quality of Experience (QoE) of traditional media has gained attention from both academia and industry. Research works stimulating additional senses like olfaction (sense of smell), haptic (sense of touch) and gustation (sense of taste) have emerged. In particular in theme parks, multisensory experiences that also offer ambient lighting effects, vibrating seats, wind generators, mist effects, heaters/coolers, etc. are appearing. Considering this growing awareness and popularity, a key research challenge is to experimentally evaluate if and how these different effects affect user QoE. In this context, there is a lack of common test content and raw data results to support reproducible research and cross research team verification. This paper fills this gap. We share: the data from the empirical study; the video content; the olfactory components employed to enrich the video; the methodologies employed and various other aspects found through experience to be important. Uniquely, this work is complemented by two datasets, obtained in two separate but related empirical studies, one conducted in the UK, and the other in Ireland.

Media-rich content plays a vital role in consumer applications today, as these applications try to find new and interesting ways to engage their users. Video, audio, and the more traditional forms of media content continue to dominate with respect to the use of media content to enhance the user experience. Tactile interactivity has also now become widely popular in modern computing applications, while our olfactory and gustatory senses continue to have a limited role. However, in recent times, there have been significant advancements regarding the use of olfactory media content (i.e., smell), and there are a variety of devices now available to enable its computer-controlled emission. This paper explores the impact of the audio stream on user perception of olfactory-enhanced video content in the presence of skews between the olfactory and video media. This research uses the results from two experimental studies of user-perceived quality of olfactory-enhanced multimedia, where audio was present and absent, respectively. Specifically, the paper shows that the user Quality of Experience (QoE) is generally higher in the absence of audio for nearly perfect synchronized olfactory-enhanced multimedia presentations (i.e., an olfactory media skew of between {−10,+10s}); however, for greater olfactory media skews (ranging between {−30s;−10s} and {+10s, +30s}) user QoE is higher when the audio stream is present. It can be concluded that the presence of the audio has the ability to mask larger synchronization skews between the other media components in olfaction-enhanced multimedia presentations.

Enhancing multimedia applications with olfactory sensations is one of the last challenges in the area. While there is evidence, both scientific and anecdotal, that olfactory cues help users in information recall tasks, there is a lack of work when the targeted information is one contained in a multimedia presentation, which is precisely the focus of this article. Accordingly, we present the results of two experimental studies. The first study measured the impact of olfactory media variation on the user's ability to perceive, synthesize, and analyze the informational content of olfactory-enhanced multimedia videos; the second study measured the impact of information content, and an information recall task in respect of user perception of the relevance, sense of reality, and acceptability of the olfactory media content, as well as the overall enjoyment of the experience. Results show that the use of olfactory media content, both pleasant and unpleasant, in multimedia displays does not significantly impact on information assimilation in a negative way. Moreover, the addition of a performance task may enhance the user's understanding of the correlation between the characteristic odor(s) and the scenario under consideration, as well as enable users to consciously learn the odors.

Olfaction, or smell, is one of the last challenges which multimedia applications have to conquer. As far as computerized smell is concerned, there are several difficulties to overcome, particularly those associated with the ambient nature of smell. In this article, we present results from an empirical study exploring users' perception of olfaction-enhanced multimedia displays. Findings show that olfaction significantly adds to the user multimedia experience. Moreover, use of olfaction leads to an increased sense of reality and relevance. Our results also show that users are tolerant of the interference and distortion effects caused by olfactory effect in multimedia.

Olfaction is an exciting challenge facing multimedia applications. In this article we have investigated user perception of the association between olfactory media content and video media content in olfactory-enhanced multimedia. Results show that the association between scent and content has a significant impact on the user-perceived experience of olfactory-enhanced multimedia.

The focus of this paper is on olfaction-enhanced multimedia applications, that is, combining computer generated smell with other media to enrich the users' experience and perception of a multimedia application. Within the general context of mulsemedia -- multiple sensorial media applications -- we review the literature and highlight challenges of enhancing (multi/mulse)media with olfaction.

The concept of synchronization is of fundamental importance in multimedia systems and applications. The focus of this this paper is on olfaction-enhanced multimedia, which concerns itself with associating computer-generated smell with other media. However, the lingering nature of smell, as opposed to the transitory nature of other media objects that multimedia applications are accustomed to, such as video and audio, means that specific attention needs to be given when synchronizing other media content with olfactory data. Consequently, this paper presents the results of an experimental study carried out to explore and investigate the temporal boundaries within which olfactory-data output in an olfaction-enhanced multimedia application can be successfully synchronized with other media objects from an end-user perspective. Results show the presence of two main synchronization regions, and that olfaction ahead of audiovisual content is more tolerable than olfaction behind content.

The experiment reported in this paper sought to discover the impact that enhancing multimedia applications with olfaction has on an information recall. In contrast to previously reported studies. our results showed that olfaction actually had a negative impact on information recall. We believe that this difference is due to the ambiental nature of olfaction in previous work, whereas in our study we used directed olfactory stimuli.

This paper presents the results of an experimental study carried out to explore, from an end user perspective, the temporal boundaries within which olfactory data can be used to enhance multimedia applications. Results show the presence of two main synchronization regions, and that olfaction ahead of audiovisual content is more tolerable than olfaction behind content.

The concept of synchronisation is of fundamental importance in multimedia systems and applications. It relates to defining and maintaining the temporal relationships between two or more correlated media objects that are combined, processed and presented together to produce a multimedia system or application. The focus of the research presented in this paper is on olfactory enhanced multimedia, which concerns itself with associating computer generated smell with other media. However, the lingering nature of smell, as opposed to the transitory nature of other media objects that multimedia applications are accustomed to, such as video and audio, means that specific attention needs to be given when synchronising other media content with olfactory data. Results highlight the existence of two perceptual synchronisation regions for olfactory enhanced-multimedia applications. Moreover, olfaction ahead of audiovisual content was shown to be less noticeable than the inverse case, of olfaction behind audiovisual content.