Smelly Ultrasound

We arenβt sure why, but [Lev Chizhov] and some other researchers have found a way to make you smell things by hitting your head with ultrasound. Apparently, your sense of smell lives in your olfactory bulb, and no one, until now, has thought to try zapping it with ultrasound to see what happens.
The bulb is somewhere behind your nose, as you might expect. This is sub-optimal for ultrasound because your nose isnβt flat, and it is full of air. Packing a subjectβs nose with gel wasnβt going to win many fans. The answer was to place the transducer on the personβs forehead and shoot down at the bulb. They made a custom headset that let them precisely target areas of the subjectβs bulb guided by an MRI.
So far, they have a sample size of two, but theyβve managed to induce the smell of fresh air, garbage, ozone, and burning wood. What would you do with this? Smell-o-vision? A garbage truck VR game? Let us know in the comments. We donβt think this is exactly how the last VR smell gadget we saw worked, but β honestly β we arenβt completely sure.