Another tidbit on scent perception differences between people — “Every Human May Have A Unique Nose”
A few weeks ago, Robin on Now Smell This posted a link to a series of videos for a symposium called Headspace that covered topics on “Scent As Design.” I played the videos in the background while I worked on something else, and I found part of one of the four to be interesting enough to go back and watch in more detail. The one that caught my attention was a presentation by Leslie Vosshall about the way people smell the same scent differently. I’ve talked about this phenomenon on the blog a number of times, so it was interesting to see that some researchers are currently looking into it. For those who are curious, the link is symposium part 3, and this topic starts at about the 25 minute mark.
Researchers at Rockefeller University studied how people perceived different odors and took blood samples from the subjects to study their DNA. The researchers found that each person had a different set of odor receptors that were functional and nonfunctional, and those differences seemed to make people perceive the odors differently. The title for that slide during the lecture was “Every Human May Have A Unique Nose.” The topic came up again at the 1 hour and 4 minute mark when they compared having nonfunctional odor receptors to being color blind but with much more subtle results since there are so many more odor receptors than color receptors, which means that losing a few makes less impact on your life for smells than for colors.
Leslie Vosshall also mentioned that they found a core set of odor receptors that almost everyone had, and vanilla was one of those with only 5 percent having nonfunctional vanilla reception. That does not surprise me since I’ve yet to find someone anosmic to vanilla, while I’ve found people anosmic to many other things. As a perfumer this makes me feel it is “safer” to use vanilla as a sweetener than to use musk, and I’m more aware of this issue now than I was several years ago. It may also help explain why vanillic bases are so popular — not only are they long-lasting, but they are also more likely to be smelled by nearly everyone.
That was really interesting. I’ve always wondered about that. I thought that maybe it was like 5 different people viewing a painting and then all 5 describing something a little different – just a case of different people focusing on different things. But why do some smells change over time? Like a perfume that at first I can’t smell at all, suddenly I can smell it a year later? Or something I try that I don’t like, later seems to be wonderful, and have so many layers to it I never noticed.
Those are excellent questions! I think it’s fairly common to have your taste in perfumes change a bit with time as you try more things and as you learn more about notes. Some notes seem like instant loves and others take some time to appreciate (that happens with some foods or drinks too). But it’s harder to explain why some people can start to smell something that they couldn’t smell before. I’ve not had that happen to me, but I’ve heard a few people say it has happened to them. I wonder what the researchers would say about that.
You’re also right of course that people will focus on different things in scents, partly from different sensitivities to the ingredients in the blend and partly from their different likes/dislikes. Reaction to scents is a complex mix of your biology (what scent receptors you have and what odors you smell most/least strongly), your upbringing and culture (what you’ve been taught to like), and your personal experiences and memories attached to various odors.
Thanks for stopping by and for bringing up some interesting questions! I think we have a long way to go to really understand scent perception. It’s fascinating though!
PS Just took a peek at your blog and it’s lovely! Your descriptions of scents are wonderful, and lucky you for winning a sample of the upcoming new Tauer rose scent Une rose vermeille! It sounds yummy!
I’ve read that Ambroxan is a key part of many amber accords, but on encountering a vial of it, I’ve found it’s one of the chemicals I am totally anosmic too. It’s fascinating to smell something one is anosmic to in the company of someone who can smell it, as it’s like someone seeing the Invisible Man. With color-blindness there is a lack of an ability to differentiate, but if someone has trouble with green they can still see there’s a tree in front of them. With anosmia, it’s as though the tree is there for a friend and not for you.
Due to this particular anosmia, I often wonder if I know what a traditional “amber” accord actually smells like. Most ambers I’ve tried have been potent and certainly haven’t been “invisible fragrances”, but when I say “amber” am I describing something quite foreign to a person who associates that with ambroxan? I wonder…
Yes, I’ve found synthetic ambers are the next most common anosmias after musks, just from my limited database anyway. Ambroxan, ambrocenide, ISO E Super, and many others give people trouble. Most amber accords use many other ingredients as well as these synths, so you’re just missing one piece with ambroxan. You may do better with more natural amber accords built with vanilla, labdanum, woods, balsams, etc. And you can probably smell some synth amber chems even though you don’t smell ambroxan. I do use ambroxan in some formulas, but I use lots of other amber ingredients too and other things can substitute for ambroxan. An all-natural amber accord can be beautiful with none of the synths. Not all perfumes that list amber as a note use ambroxan, and in fact bescause that’s one of the more expensive synth amber ingreds, some of the cheaper ones may be used more often. I’d never use just one synth chem like that and call it an amber accord though — it’s just one piece.
Your analogy with seeing the colored object in front of you regardless of color but having ambroxan be totally invisible is apt and descriptive! Thanks!
This is a fascinating discussion. I am hypersensitive to civet and can be totally overwhelmed by even a trace amount of this, which other people don’t seem to detect. It makes me think that – vanilla aside – we may all be alone with our own idiosyncratic noses!
I am a huge fan of Opal, btw. My friend said: “Oh no, that is too sweet”, and I thought: ‘What??'”
I rest my case.
Yes, the way people interpret finished scents and individual ingredients can vary tremendously. I’ve mentioned how I get feedback on Tabac Aurea that varies from “very dry” to “gourmand.” Sweetness level depends on which things you smell (do you smell the sweet musks, ambers etc or are they invisible to you), and whether the sweet things get overrun by being sensitive to something dry in the blend (like your civet sensitivity), and also your general sweetness tolerance and mood at that moment. Opal is on the sweet side to me, but the citrus note in it helps offset the sweetness. People do vary on that one too, partly by whether they like musk since it’s a musk scent.
I do believe we all have unique noses, all with basic things in common but with subtle differences. I think when we find a “scent twin” they may have a lot of common receptors to what we have. It’s a fascinating topic. I think it calls for tolerance, lol. Tolerance when we hear someone describe a scent totally different to how we perceive it. We just have to remember none of us is crazy — we just have different noses. That may be why we find favorite perfumers too, if we have similar receptors to the perfumer. Of course preferences come into play too, but I think it is a combination of what you like and how your nose works that determines your reaction to scents.
Thanks for stopping by, and watch out for that civet! 🙂 I’m a bit sensitive to civet too. I do ok with it in blends but it is a tough one for me to work with (diluting it is not fun). I find castoreum easier, but some people are just the opposite.