Researchers launch a new smell training device for rehabilitation after Covid-19

Smell training used to be mainly a thing for wine enthusiasts, gourmets, and perfumers. But Covid-19 changed all that, and now Malmö University researchers have launched a new smell training device.

The single most obvious symptom of Covid-19 is smell loss, but long before the pandemic, Simon Niedenthal, a smell researcher at the School of Art and Communication, saw a need for structured smell training outside a clinical environment.

By smelling different things you have at home — such as spices — every day for fifteen to twenty minutes is like any other workout. When you repeat an activity, you get better at it."

Simon Niedenthal, Smell Researcher at School of Art and Communication, Malmö University

This idea created the concept of Exerscent, a combination of a physical smell training device which connects to a computer. The aim is to collect points by identifying different scents; then the training results are documented and assessed by caregivers and researchers.

The device design is free to download and can be assembled from 3D printouts. The electronics and optional fragrances can be purchased commercially.

"The point of Exerscent is to make smell training available to as many people as possible. It is easy to assemble and, according to our study, easy to use," says Niedenthal.

The study involves 11 participants who all reported a normal sense of smell. Participants recognised on average 66 per cent of the scents and thought it was easier to identify vegetables and spices, than fruits and flower. This is where the researchers see a potential with increased smell training for a higher hit rate.

Exerscent can be used for rehabilitation after Covid-19, or other viral infections that have caused smell loss. But it is also an option for professionals in food, drink, and fragrance; in addition, the elderly may benefit as the sense of smell deteriorates with age.

The researchers also believe it could help with children who are picky about their food.

"Acceptance and approval are about habit. Leaving the first step to smelling food, instead of eating it, could be a way to gradually increase tolerance. Since it is a computer game, it may also be suitable for children," says Niedenthal.

Niedenthal developed Everscent with his colleagues Johannes Nilsson and David Cuartielles at the School of Arts and Communication, and Teodor Jernsäther, Maria Larsson and Jonas K. Olofsson at Stockholm University.

"When asked which sense you would not want to lose, most people would probably answer sight or hearing. But those who have now lost their sense of smell better understand what a loss it actually is. In dementia, for example, the sense of smell is the first thing that is lost. There is a connection between scents and memories — I think most people feel that intuitively," adds Niedenthal.