This ‘White Smell’ Machine Can Cancel Odors

A new machine evaluates a room’s smell in order to create the exact combination to counter that odor.


A new machine could be used to counter odors. Photo credit: martin on Flickr, via Creative Commons

Traditional air fresheners aren’t always able to get the job done. That’s where a new smell-analyzing machine could really come in handy. It evaluates a room’s smell in order to create the exact combination that will counter that particular odor. The machine was invented by two brothers: an IBM researcher and an Illinois University assistant professor in the computer engineering department. The duo says the machine is capable of producing “olfactory white” (white smell), which serves a similar function to white noise.

Comparing smell to a signal

The brothers have developed an algorithm that analyzes the chemical compounds in an odor. It then comes up with a compound that is able to balance out the original smell, thus producing olfactory white.  


Lav R. Varshney. Source: University of Illinois

“Every smell a human encounters is composed of a number of chemical compounds,” Lav Varshney, one of the inventors, said in a statement. “Each of those compounds can be matched with other compounds that cancel out its smell.”   

They came up with the idea for the machine during a casual conversation about white smell. In order to cancel a radio signal, the researchers say, it is necessary to find the perfect wave that cancels it. The same goes for odors. The brothers compared smell to a signal and realized by treating it like one, they might be able to cancel it out.

Creating an algorithm

It took the duo a few weeks to create an algorithm that worked. “Once we had the basic ideas down, the math was actually pretty straightforward,” Lav Varshney said. “Some of the signal processing ideas we used have been around since World War II. We applied the same mathematical ideas that cancel signals to cancelling smells, but with some modern mathematical tricks.”

This machine has implications for various other sectors, including the food industry. It could potentially enhance the taste of food through a practice called food steganography (diminishing certain smells by enhancing others). Consumers are often turned off by a food item due to its smell. However, the Varshney brothers’ machine could create an edible additive capable of cancelling certain smells.