*2.2. Multi-Sensory Art*

The recent growing interest in multi-sensory experiences within the scientific and HCI community has also been accompanied by a growing interest in those technologies by artists and museums. For example, in [9], a prototype called SensArt, which uses music, vibration patterns, and temperature to translate descriptive and emotive qualities of the artwork to the user, is designed and tested. The tests with 12 participants showed that most participants preferred the multi-sensory experience over the normal one and commented that they would visit museums more often if those types of experiences were more available.

Tate Sensorium [10] is a multi-sensory display that was exhibited at the Tate Britain art gallery of London. Its authors set themselves to explore new ways of experiencing art while researching and gaining design insights related to multi-sensory systems. One of the most interesting results after real on-field testing with users was the conclusion that multi-sensory experiences, in general, do make art more engaging and stimulating.

It can be observed that in most multi-sensory art applications some type of sound of musical feedback is included. Research has shown that mixing music with visual art increases the emotional experience of the user [11]. Additionally, as can be inferred from previous works' results, multi-sensory systems seem to increase the engagemen<sup>t</sup> of the spectator and enhance the art exploration experience. Similarly, one of the goals of our sound-temperature multimodal system for conveying color is to enhance the artistic experience for visually impaired users. Particularly, we expect the art engagemen<sup>t</sup> to be raised and the experience and memorization of colors to be improved. This manuscript is the first iteration towards that goal: the definition and design of the multi-sensory color coding.

### *2.3. Multi-Sensory Assistive Devices*

Multi-sensory systems have also been implemented as assistive devices for the visually impaired people. In [12] a multi-sensory picture book for children with visual impairment was presented. The work provided visually impaired children with a multi-sensory experience consisting of touch, sounds and smell, which was integrated with the storytelling. User tests with a total of 25 children showed the potential of multi-sensory experiences for increasing engagemen<sup>t</sup> and enhancing the learning and artistic experience of children. The use of smell as a sensory modality is particularly interesting because of its implementation and how uncommon smell interfaces are. The olfactory device is contained inside the book's page and the fragrance can be smelled as it is emitted from a small hole in the center of the device panel. Similarly, our work also investigates a less common interaction modality by implementing temperature cues.

Mapsense [13] is a multi-sensory interactive map for visually impaired children. The map consists of a colored tactile map overlay on top of a touchscreen, speakers, and conductive tangibles. The tactile map overlay has some point of interest which can detect the conductive tangibles when placed on top. Additionally, the system provides the user with audio feedback communicating the name of a city when a point of interest is tapped twice with the finger. Based on that premise, there are several modes available: guiding function, audio discovery, and navigation. The guiding function consists of vocal indications guiding the user to the destination (one of the points of interest). On audio discovery, sound effects (such as the song of water when sailing or religious chants when reaching a church) were trigger while navigating the map. Lastly, the navigation mode allows the user to navigate between "points of interest", "general directions" and "cities".

There are also multi-sensory art exhibitions that are designed specifically for visually impaired people, so they can be considered multi-sensory assistive art exhibitions. The "Feeling Vincent Van Gogh" exhibition is one of those types of exhibitions aimed at the visually impaired [14]. The artwork is communicated to the users through a large variety of interactive elements such as sounds, smells, and 3D versions of Van Gogh's most famous artworks. The highly detailed 3D reproductions allow the visually impaired spectator to appreciate the brush strokes of Van Gogh. In addition, the visual part of the exhibition is carefully taken care of so sighted people (either by themselves or accompanying a visually impaired person) are also able to enjoy the multi-sensory experience.
