The Fourth Sense: How Can Smell Deepen Virtual Immersion?

Virtual reality (VR) is based on the notion of creating a realistic world within the confines of an immersive device, but from where we stand now, they can be a bit lacking. While we have made huge inroads on the visual, sound and feedback side of things, virtual environments remain a little lacklustre because there is no easy way to simulate the sense of smell, and that can actually leave a huge hole in the VR experience.

The significance of smell is frequently disregarded by many, and we frequently fail to see how important it is to include smell as a major sense. On the other hand, a life devoid of smell would be somewhat uninteresting. Humans are able to identify potential dangers through the use of their sense of smell, which alerts us to the presence of a potential gas leak in a building and enables us to detect smoke before we ever see it billowing from beneath a door. Our emotional brain is also activated when we smell something. According to a number of studies, fragrances are responsible for roughly 75% of our everyday emotions, making smell a major sensory input. The appropriate aroma can evoke a variety of feelings in us, including vigour, joy, anxiety, or even disgust. All of these are essential to being able to have real emotions with an experience and a growing number of system developers are keen to incorporate smell into the experience. 

It is estimated that people can smell anywhere between 10,000 and 10 million different odours, and it is possibly considerably more than that. There is a large amount of individual variation in the degree to which people are sensitive to scents due to the fact that each of our noses contains a unique composition of odour-detecting cells. In point of fact, when various people smell the same material thing, their interpretations of what they smell may be very different. Odours have the ability to affect many facets of our lives, including our memories, our feelings, and our moods, due to the fact that information about smell is delivered to many regions of the brain. Healing methods have been used in many different civilizations for thousands of years, including ancient China, India, and Egypt. Some of these rituals involve the use of fragrant plants. For instance, the purpose of aromatherapy is to enhance both one’s physical and mental health by making use of essential oils extracted from flowers, herbs, or trees.

Because odours can enhance an experience so much, many developers recognise the need to incorporate this sense into the overall adventure, and greatly enhance virtual interactions. But how can odours – which may be highly specific and identifiable – be incorporated into what is essentially an electronic system? Unsurprisingly, a number of companies are working flat out on this.

In the real world, odours and smells are conveyed to us when molecules in the air drift into the nose, which causes specialised nerve cells in the upper airway to send impulses to the brain. This is how odours are perceived. In the most recent studies, which were carried out at the Imagineering Institute in the city of Nusajaya in Malaysia, on a total of thirty-one test participants, the researchers inserted electrodes into the nostrils of the test subjects in order to administer weak electrical currents above and behind the nostrils, which is where the neurons are located. The researchers were successful in conjuring up ten distinct aromas in virtual reality, some of which included fruity, woodsy, and minty notes. With the potential areas of the nose identified, it became an engineering task of associating stimulus with actual, reliable results.

In the current systems, by first gathering odour characteristics with biosensors and then utilising software tools to analyse and present the odour data, digital olfaction attempts to simulate the way in which humans smell. The signatures are then interpreted by intelligent software tools, which classify them based on a smell database of previously recorded odours.

Olfactory specialists OVR Technology released their Architecture of Scent Platform in the year 2020 and have been further adapting it ever since. The package includes the IO fragrance Device, which can be attached to an augmented reality or virtual reality headset, a software suite that includes a plug-in for content creators that allows them to add fragrance triggers and geometry to virtual reality objects, and the company’s in-house developed Scentware. In virtual reality training and wellness applications, the combination of this Hardware, Software, and Scentware platform produces exact fragrance molecules based on the user’s interactions, which can assist deliver greater immersion and presence for the user. 

The need to develop olfactory systems to run alongside the visual and auditory inputs are likely to be a major requirement for the next generation of VR and AR equipment. The incorporation of smell into the VR experience has the potential to create a number of additional good benefits for the user, because the incorporation of touch and sound into the VR experience has served to deepen the immersion that is available to today’s virtual explorers. When we explore virtual reality and augmented reality landscapes, the more of our senses that we can engage, the more realistic these settings will become.   

But, equally, including a sense of smell in virtual reality presents a number of obstacles if it goes wrong. Because we are generally very good at identifying even quite subtle odours, there is a possibility that our sense of immersion will be disrupted as well if the producers do not put in sufficient time and effort to ensure that the smell is accurate. There is still a large amount of research to be done before the sense of smell can become as widespread as sight or sound in virtual reality systems. On the other hand, the evidence suggests that a great number of technologists are already well on their way to discovering the actual power of immersive fragrances. Time will tell how good these are at fooling our brains into believing that they actually exist in a virtual environment.