It's common knowledge that most humans have five senses. But, some people are attempting to rewire those fundamentals into more interesting experiences — like seeing with your tongue and listening to music with your teeth.

"The brain is plastic and we can definitely tap into the higher sensory processes through other sensory stimuli," says Aisen Caro Chacin, an artist, researcher and university professor. "I think that if you give an input to the brain, it will figure out how to map it and make sense of that information."

Chacin created four devices to rewire people's senses for a project called Sensory Pathways for the Plastic Mind.

One device allows wearers to smell the time.

The watch contains small bulbs that hold various scents, which are released at various times:

  • 12 a.m. - 6 a.m. is chamomile.
  • 6 a.m. - 12 p.m. is coffee, "to start waking you up slowly."
  • 12 p.m. - 6 p.m. is paper and tarnish, "because I wanted to make it smell like money."
  • 6 p.m. - 12 a.m. is whisky and tobacco.

While these smells are Chacin's favourites, they can be adjusted to suit the wearer's preferences.

The watch also contains small amounts of chemicals to promote the desired state of being. For example, there's a touch of caffeine during the coffee-scented hours and some melatonin in the evenings.

Another device, dubbed the play-a-grill, transmits sound using bone conduction hearing. It allows users to hear music through their teeth when the retainer-like device is placed in their mouth.

Her final two creations in that project are headphones that enable people to use echolocation — similarly to bats or whales — and a contraption that helps people see with their tongue.

While her work is artistic in nature, Chacin believes it could become assistive technology for some people.

Brainport lets tongues see

In 2011, Jose Neto became one of the first Canadians to test a similar device after being blinded by a stray bullet several years earlier.

Tongue vision

A retired Marine who lost both eyes in an explosion in Iraq demonstrates BrainPort, a unique technology that helps people identify objects through small shock patterns on their tongue. (Gene J. Puskar/The Associated Press)

He was selected to participate in a medical study for Brainport, a device that turns visual stimuli into small, electrical signals on a person's tongue. It's made up of sunglasses with a small camera attached to the front and a device, slightly larger than a postage stamp, that is placed in a person's mouth.

When a person is walking down the street wearing Brainport, it will send little shocks in the form of a stripe in the middle of their tongue, representing the sidewalk, Nero explains. The shocks feel like champagne bubbles, fizzy soda or Pop Rocks candy.

"It becomes natural very quickly," says Neto, who spent two weeks testing the device.

Sarah Ballantyne helps train users to interpret Brainport's signals on their tongue. In a training session, she helped Spark host Nora Young identify a coffee mug while wearing Brainport.

"The sky's the limit with it," she says.

Eyeborg hears colour

​After being born with a form of total colourblindness, Neil Harbisson spent a decade developing what he calls the eyeborg — a device that allows him to hear colour.

In 2004, the contraption started out as a webcam connected to a portable computer and a pair of headphones.

'If I go to an art gallery, I can listen to a Picasso or an Andy Warhol.' - Neil Harbisson, eyeborg developer

It’s since evolved into what Harbisson says is more a "body part" than wearable technology. It's now an osseointegrated implant connected to Harbisson's body.

Frequencies correspond with specific colours.

"If I go to an art gallery, I can listen to a Picasso or an Andy Warhol. So the painters have become composers," he says. "And, when I go to a concert, I experience colour."

He says he can also hear infrared and ultraviolets.

Harbisson admits he feels lonely sometimes, waiting for others to extend their senses and share in his experience.

Others like Frank Swain, who partially lost his hearing in his mid-20s, has now hacked his iPhone and connected it to his hearing aid so he can hear WiFi signals. Swain, like Harbisson, calls himself a cyborg.

"Some day, there'll be more people, I guess ... But, yeah, I'm just here, waiting," says Harbisson.