We Induced Smells With Ultrasound • Hacker News Board

Re: We Induced Smells With Ultrasound

#151

Post by Sxubas » Sun, Nov 23, 2025, 1:10 PM UTC

I'm a little bit skeptical but i dont have any objective argument or experience in the field to justify it. I didn't want to post it, but I was surprised that almost no one in the hn comments had the same feeling.

Don't get me wrong, I would love this finding to be replicable, it would be pivotal as what other nerves could we stimulate to change perception (think pain, mental health issues, loss of senses).

Also, I wonder if this could take us closer to understand a little bit more of how the brain works. Like this could be a great way for normalizing 'inputs' and see how different brains react to it.

Very very exciting news, but I will hold on my hype until someone else can replicate this result.

Re: We Induced Smells With Ultrasound

#152

Post by johnp314 » Sun, Nov 23, 2025, 1:12 PM UTC

Genbox wrote: post #133

RedAlakazam wrote: post #125

As someone who was born without a sense of smell this is incredibly intriguing to me. I've always wondered if there's gonna be a time in my life where I'd be able to experience *any* kind of smell through some new scientific discovery. And maybe this is it. Could I shoot you guys a message when I make my way down to Caltech to try this out someday? :)

The condition is called Anosmia and can stem from different sensor and brain conditions. It would be interesting to try the technique on people with these conditions to map the different kinds of olfactory failures. If you get in contact with the researchers, please let us know how it went.

Please include me also in contacts. I developed anosmia about 8 years ago (well before COVID). I truly wish there were some sort of 'cure' that would restore even a small amount of my sense of smell.

Re: We Induced Smells With Ultrasound

#153

Post by isoprophlex » Sun, Nov 23, 2025, 1:28 PM UTC

brilee wrote: post #143

isoprophlex wrote: post #111

Earlier quoted context omitted.

I was an organic chemist, and as such worked I've worked in various "wet" laboratories. All of them had store rooms and cabinets with hundreds or thousands of bottles filled with horribly smelling goop. Besides the occasional terpenoid (naturally occurring things smelling like menthol, cloves or cinnamon) nearly everything there was liquid death. These smells have everything: Harsh solvent-like stuff like strong alco…

I could have sworn that sickly sweet smell was the smell of various phosphine reagents? Just my vague recollection of my time in lab from 15 years ago.

Phosphines, for me, were either odorless (for heavy ligand like things like triphenylphosphine) or absolutely rancid fishy mixed with a burnt chemical note. thankfully I never inhaled too many of the light organophosphines, they aren't too healthy...

Re: We Induced Smells With Ultrasound

#154

Post by b800h » Sun, Nov 23, 2025, 1:42 PM UTC

And this is why high-powered prenatal ultrasound has always concerned me (in fact the NHS advises against the commercial scans for this reason).

Re: We Induced Smells With Ultrasound

#155

Post by NedF » Sun, Nov 23, 2025, 1:46 PM UTC

Sxubas wrote: post #151

I'm a little bit skeptical but i dont have any objective argument or experience in the field to justify it. I didn't want to post it, but I was surprised that almost no one in the hn comments had the same feeling. Don't get me wrong, I would love this finding to be replicable, it would be pivotal as what other nerves could we stimulate to change perception (think pain, mental health issues, loss of senses). Also, I w…

[dead]

Re: We Induced Smells With Ultrasound

#156

Post by jasongill » Sun, Nov 23, 2025, 1:48 PM UTC

b800h wrote: post #154

And this is why high-powered prenatal ultrasound has always concerned me (in fact the NHS advises against the commercial scans for this reason).

The NHS does nothing of the sort, in fact, they recommend them as safe and routine.

https://www.nhs.uk/pregnancy/your-pregnancy-care/ultrasound-...

> The scans are painless, have no known side effects on mothers or babies, and can be carried out at any stage of pregnancy.

If you read the linked article, you'd see that most of it focused on how extremely hard it was to get the ultrasound to do anything - it required an MRI and exact positioning of the ultrasound transducer. I doubt that 5 minutes of being gently prodded through the skin and fat is going to harm a child. Also, ultrasounds (and waves and radiation of all sorts) are passing into your body at all times, so it's not like they are exposing the fetus to something rare or unusual.

Re: We Induced Smells With Ultrasound

#157

Post by HeinzStuckeIt » Sun, Nov 23, 2025, 1:50 PM UTC

Reminiscent of a finding reported at a neurology conference in the 1960s that served as the epigraph to J.H. Prynne’s collection of poems Wound Response:

“Of particular interest in the present context are the observations made on patients whose middle ear had been opened in such a way that a cotton electrode soaked in normal saline solution could be placed near the cochlea. A total of 20 surgically operated ears were studied. Eleven patients heard pure tones whose pitch corresponded to the frequency of the sinusoidal voltage applied to the electrode… One patient reported gustatory sensations.”

Re: We Induced Smells With Ultrasound

#158

Post by big-and-small » Sun, Nov 23, 2025, 2:14 PM UTC

simsla wrote: post #140

exr0n wrote: post #105

Earlier quoted context omitted.

Super interesting! That would make sense, because a lot of the nose is presumably dedicated to smelling evolutionarily-relevant smells, most of which are "smells bad, avoid this". The method is very crude right now, but maybe with more fine-grained targetting we could better tune the smell profile.

Good / bad / unclassified. It makes sense for unclassified to smell worse than good, and it'd probably be the biggest category by a long stretch. (Pure speculation.)

And even good / bad is sometimes subjective and brain can adjust to it depend on whatever you like the taste for instance. Tell you this as a big fan of durian. Since there a lot of chemicals responsible for smell brain override reaction to fruit once you love the taste.

Re: We Induced Smells With Ultrasound

#159

Post by omnicognate » Sun, Nov 23, 2025, 2:22 PM UTC

Interesting that burning was one of the smells. AFAIK that often comes up in neurological problems like strokes and epilepsy, so is it a particularly coarse sensation (like exciting all the different specialised neuerons at once)?. I imagine there's going to be a long challenge of targeting this to elicit more refined scents.

Re: We Induced Smells With Ultrasound

#160

Post by bee_rider » Sun, Nov 23, 2025, 2:23 PM UTC

krackers wrote: post #7

I'd maybe make a hypothesis that a large portion of the space is "bad" smelling stuff: smoke or garbage. When people had covid-induced parosmia, it almost always seemed to be bad smelling stuff.

I wonder if we search for the worst smell, via optimization, is does this make it a big, not very steep optimum? Or maybe all unknown smells are a little bad, but the worst smell is some familiar badness.