This episode was written and produced by Lindsay Redifer.

Synesthesia is a neurological condition where one sensory experience gets combined with another, meaning someone might hear sounds when they eat, or see colors when they listen to music. So what exactly is synesthesia? And what’s it like to go through life with these unique sensory connections? Featuring the voices of neuroscientist Dr. Richard Cytowic and five people with synesthesia.

MUSIC FEATURED IN THIS EPISODE

Golden Boy (instrumental) by Kaptan
Pink Blossoms by Sound of Picture
Serenity by Sound of Picture
Crystal Bloom Percussion by Sound of Picture
Picnic March by Bitters
Friction Model by Limoncello
The Crisper by Confectionery
The Cornice by Confectionery
Dusting by Confectionery
Gymnopedies 2 by The Nocturne

MUSIC DISCUSSED IN THIS EPISODE

Innocence by Bjork
Venus As a Boy by Bjork
Pluto by Bjork
George Gershwin's Rhapsody in Blue played by Libor Pesek and the Slovak National Philharmonic Orchestra
Bad Guy by Billie Eilish
Purple Haze by Jimi Hendrix

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Check out Dr. Richard Cytowic’s work at cytowic.net.

Check out Joel Salinas's book Mirror Touch: A Memoir of Synesthesia and the Secret Life of the Brain.

View Transcript ▶︎

You’re listening to Twenty Thousand Hertz. I’m Dallas Taylor.

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Andie: The name Dallas Taylor is pink, yellow and blue to me. And Taylor for me is purple and orange and pink.

David: The sound of Dallas Taylor's voice is a blue to black, and it’s very sparks. Sparks across my chest. But it has a softness to it. It's not like a sharp, it's like a soft spark that kind of pops as he speaks.

Kylie: The name Dallas Taylor tastes like a chip with some meat on it and dinner rolls.

The people you just heard have a neurological condition called synesthesia. People with synesthesia, called “synesthetes,” experience sounds, tastes, and even numbers and letters in combination with their other senses. So, for example, taste might have a color. Or hearing a song might produce a physical sensation on their skin. Or a name like Dallas Taylor might taste like a chip with some meat on it, and dinner rolls.

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Synesthesia may sound unusual, but it’s actually more common than you might think. Studies suggest that as many as one in 25 people have some form of it. We know a fair amount about it now, but for a long time, scientists weren’t even sure that it existed.

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Richard: Back in the ‘70s, when I started with this, you know, the dogma at the time is that we had five senses that traveled along, single tubes, as it were, and there was no mixing between the two, I mean that was the dogma.

That’s neurologist Richard Cytowic. Before the word “synesthesia” was widely known, he stumbled across the term by chance in the med school library.

Richard: I used to go down to the sub-basement of the library in medical school while I browsed these old, dusty books that nobody had checked out in a long time. I came across Luria's book on The Mind of the Mnemonist, that is a memory expert. The reason that he could remember limitless amounts of information is that he had a fivefold synesthesia. He had all these extra hooks to hang things on.

Richard: And I thought, "Ooh, what a cool word." Everybody knows “anesthesia,” no sensation. “Synesthesia” means “joined or coupled sensation.” “That's pretty cool,” so I filed that away in the back of my head.

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The first time Dr. Cytowic encountered someone who actually had synesthesia was when he was invited to a dinner party.

[SFX: dinner party: light chatter, light jazzy music, drinks]

Richard: My new neighbor invited me over to meet some friends. He delayed our seating by saying, ”It'll be a few more minutes. There aren't enough points on the chicken.” So, his friends laughed and said, ”Michael, what are you smoking now?” But the host, Michael Watson turned to me and, ”Oh, you're a neurologist. Maybe you'll understand. When I taste something, I feel it on my face and in my hands. With an intense flavor, a feeling sweeps down my arm and I feel shape, weight, texture, and temperature as if I'm actually grasping something.”

Michael Watson would later become the main subject of Dr. Cytowic’s book, The Man Who Tasted Shapes. But when Dr. Cytowic first told his colleagues about Michael, they were pretty skeptical.

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Richard: They immediately said, Well, what's his CAT scan show?" I said, "No, no, no. You don't understand. He doesn't have a hole in his head, something missing. He has something extra." They looked at me like I was insane and they said, ”Man, this is too weird, too New Age. You better stay away, because it's going to ruin your career.”

A CAT scan can show you the physical state of someone’s brain, but it can’t tell you much about brain activity.

Richard: The CAT scan would not show anything because it couldn't possibly be seeing anything that had to do with behavior. I mean, if somebody had, "My memory's no good," you wouldn't give them a CAT scan because that wouldn't show anything. You have to remember that a dead person has a normal CAT scan because it's a test of anatomy, just seeing that the pieces are all there.

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Because synesthesia doesn’t show up on a CAT scan, Dr. Cytowic had to soldier on in the face of some pretty intense doubt.

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Richard: The first 15 years, I dealt with incredible hostility, like my colleagues, ”This is going to ruin your career,” and people witheringly would say, ”Oh, this cannot possibly be a real brain phenomenon. They're just making it up. They just want attention. They're simply remembering refrigerator magnets or coloring books and that's why A is red and D is green and so forth.” Or “These are just artists and everybody knows that artists are all crazy.”

Lots of doctors just assumed these people had taken too many drugs.

Richard: Then of course, the last would be, ”Well, they're just having residual hallucinations from their drug use, pot and LSD, in the past.” So, I was really fascinated by the hostility of the reaction, because basically this is just a first person experience and so, what's the harm in looking at it? But this is like, ”Don't go there.” This is like, the evil vampire, “You've got to hold up a cross and garlic, don't you dare look at this thing.”

But as brain imaging improved, neurologists like Dr. Cytowic were able to prove that people with synesthesia had measurable differences in their brains.

Richard: It took the new functional scans, the functional MRI and magnetic resonance scans to start to show that there were differences. A person who had colored hearing, they saw colors when they heard words, and you put them in a scanner, [SFX] sure enough, when you read them English words or even nonsense words that sounded like words, the color area of the brain activated and you could see that, so yes, they were seeing colors.

In other words, Dr. Cytowic was proven right.

Richard: I was saying, “Synesthesia is real and maybe it's our theories that need to change,” and that turned out to be true. So we've totally revised the way we think the brain is organized.

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The area of the brain that registers color is called the V4. If you want to find your V4, it’s at the back of your head, just up a bit up from where your spine reaches your skull. In an MRI, you can watch the V4 light up when someone sees a color. But for synesthetes like 20K listener Andie Blaine, the V4 is also activated by music.

Andie: Every single song is one big moving painting.

Andie: So to me, certain drums are more colorful and like a blast of color, for example. I'm trying to think of what Bjork song it would be. [Music clip] “Innocence,” yeah That song has a lot of kick drums in it. And a lot of bassy kind of percussion, but [Music clip] "Venus as a Boy" has this shiny bell type of percussion. And to me that's visually very satisfying.

For Andie, a dense song can conjure a fantastic light show.

Andie: Pluto is a song in which this really speedy, glitchy, techno beat runs throughout the whole thing [Music clip]. it's a whole big moving picture of color, shape it's like a sharp beat that's a bunch of little lights together. her voice is very dewy and wet and shiny. Shiny like you would see on like a really nice piece of wood, not shiny in the sense of metallic. And then the strings are kind of like a big blanket of well it does look like strings to me, but in a very colorful, wispy way that kind of blankets the song.

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When someone with synesthesia says a name tastes like noodles or a song feels like electric sparks, they're not being metaphorical. That’s actually how their brain experiences those things. David Hopper is another listener with synesthesia. Specifically, David has audio-tactile synesthesia, and experiences sounds as physical touch.

David: Some sounds have a rubber texture. A trumpet, for example [SFX], when I hear the sound of a trumpet, it's like a tennis ball being rubbed across my forearm. Not rolled, but rubbed [SFX]. And it generally has a green color to it.

David works at a noisy restaurant, so he has to filter out a lot of sounds. Otherwise, he’s at their mercy.

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David: So a restaurant I was working in at one time, whenever they cleaned the grill top with a brick. It's like a big brick of pumice, but it's black. Anyhow, it would do this squeak [SFX] and it hurts, but it makes me instantly angry.

David: Another one was a big box of plastic spoons. The bottom fell out and all the spoons spilled on the floor [SFX], and that literally felt like ripping up on my skin,

David: The public transit train has a bell whenever it goes over crossings that literally shoots, and it feels like black to red needles shooting up my elbows [SFX]. Kind of a painful one, but it's not so painful that it's debilitating.

David: There's a walkway that goes under a pretty busy bridge, and it has this weird grate [SFX]. And whenever I walk under that bridge, that's a weird one because it literally blacks out my vision. And I lose all sense of like, if I'm facing North, South, up, down. Literally I just call it shutting me down.

David: You know those mini home meditation fountains? [SFX] Like the water trickle running all the time. Those aren't a very pleasant feeling for me. It's almost like a thing would crawl up my spine [SFX]. Like you would think of a big millipede or centipede crawling up your spine.

David: I don't physically see it. It's just like how I feel.

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But David has plenty of positive experiences with synesthesia, too.

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David: I really like classical music. I like pure instrumentals. “Clair de Lune” is one that really just has this, just has this flowing velvety feeling. And it's very like a blue-green, almost like a sea foam. But it rises and falls as well as the color does too. It'll get darker and lighter as it goes through.

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The exact cause of synesthesia is still unclear. We know it’s at least partially genetic, but it likely involves multiple genetic factors interacting with each other. So unfortunately, there’s no single “synesthesia gene” that we can test for.

As for why this condition evolved in the first place, one theory is that it helps with creative thinking.7 In fact, studies indicate that synesthesia is about seven times more common in artists, poets, and novelists than it is in the rest of the population.4 In recent years, lots of famous musicians have spoken publicly about having synesthesia. That’s coming up, after the break.

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MIDROLL

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Synesthesia is a condition where the experience from one sense shows up in another sense, so a person might see sounds or taste colors. Here’s how Heather, a Twenty Thousand Hertz listener, describes her experience.

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Heather: I have audio tactile synesthesia, which means that I feel the sounds that I hear. To give you some examples, Stephen Fry’s voice feels like a heavy fleece blanket, pulled fresh and warm from the dryer.

This is what Steven Fry sounds like…

[SFX Clip: Stephen Fry: So I’m trying in the books to recreate the relaxed feeling of sitting around the fire listening to stories, which I think is a primal thing. Listening together.]

Heather: That’s one of the pleasant examples. The frogs in Puerto Rico that go “Coqui, coqui,” [SFX] they feel like wet fat cold raindrops on my skin.

Some people even experience multiple forms of synesthesia. Here’s Joel Salinas, a neurologist and scientist who also has synesthesia.

Joel: So, for example, for me, tastes can also have sound tied to them. So, if I bite into a strawberry, [SFX: Juicy bite] especially if it’s barely ripened, I experience the sound of crashing cymbals [SFX: Cymbals], as well as little tinges of aqua, kind of little splashes of aqua.

Joel: But in the other direction, with sound being translated into a visual experience, specifically, I think about the trilling clarinet of Rhapsody in Blue, [Music clip] and almost always it will evoke this kind of bright slithering serpentine figure at the base of my tongue that tastes like blueberries perfumed lightly with fresh tire tread.

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Sometimes, the synesthetic experience can be even stronger than the regular experience from that sense. So while a firetruck might look red, the siren noise it makes might seem so green that the person thinks of firetrucks as more green than red.

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Richard: I think of one linguist, who has colored taste and, he also has colored music and all that, but he loves blue foods, but his blue foods are milk which is white, oranges which are orange, and meat which is sort of reddish purple but they're all really blue, and he has a favorite concoction that he makes called “chicken a la mode,” and this consists of a bed of spinach on which he puts a sauteed chicken breast, topped with a scoop of vanilla ice-cream, and drizzled with orange juice concentrate. Now, he only makes this when his wife is away because she thinks it's disgusting, but for him, he says it is so intensely blue. Everything is blue, there's different shades of blue, they're moving, they're overlapping and every bite is just fantastic.

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But having synesthesia allows people to do more than just enjoy a fantastically blue meal. It can also inspire creativity.

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Richard: So the painter David Hockney started painting sets for operas and he had never painted for music before. There was an interview in Art in America with him and he's talking about in the Ravel Opera L'enfant et les Sortileges, he talks about painting the tree and he says, "It has a certain weight to it," and I thought, "What do you mean it has a weight to it?" And he's saying things like “the shapes dictate themselves”, “his arm just moves according to the music,” or, “the blue has a certain gravity to it…”

Dr. Cytowic suspected that David might be synesthetic, so he reached out.

Richard: He wrote back after about four months and said, ”Dear Dr. Cytowic, I've carried your letter around with me all these many months wondering if I should answer.” That is, would a scientific inquiry destroy the magic of his experience. Of course, it didn't so I visited him out in Los Angeles for two days and we did some experiments. Indeed, he is synesthetic.

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There have also been lots of famous musicians who’ve spoken publicly about having synesthesia. Here’s Lorde talking to late night host Seth Meyers about how having synesthesia affects her music.

[SFX Clip: Lorde - So, for me, music and words kind of have colors and textures and forms, and it’s like this weird abstract thing, but making music is like a really visual process for me.]

Lorde goes on to say that she tries to avoid describing music in terms of color when she’s working with people in the studio.

[SFX Clip: Lorde - Yeah, I try hard to keep the color things away from, like, synesthesia muggles, ‘cause they feel like it’s super annoying. But, I would definitely, like, I would kind of - I would slip and be like - “It just doesn’t look very nice,” and he would be like, “What do you want me to do with that information? Like I can’t—There’s nothing there.”]

Billie Eilish says the condition makes her approach her art from every angle possible. Here she is in one of Youtube’s Artist Spotlight Stories:

[SFX Clip: Billie - I think visually first with kind of everything I do. And also, like, I have synesthesia, so, everything that I make, I already am thinking of what color it is, and what texture it is, and what day of the week it is, and what number it is, and what shape.]

In an interview with the Zach Sang radio show, Billie describes how she associates her song “Bad Guy” with the number seven.

[Music clip: “Bad Guy”]

[SFX Clip: Billie - I don’t know why. I think it’s because “Bad Guy” is yellow in my head, and the number seven is yellow. And the ending of “Bad Guy” is like this red part. In my head, like it’s red.]

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Other musicians who have described experiencing sounds as colors include Duke Ellington, Stevie Wonder, Billy Joel, Pharrell Williams, and Kanye West. Synesthesia may have even inspired one of the most famous rock songs of the 60s. Guitarists often call a dominant 7 sharp 9 chord the “Jimi Hendrix chord” [SFX] because Hendrix used it so often. But Hendrix himself allegedly called it the “purple chord,” and wrote his song “Purple Haze” around it.

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Jazz musician Adam Neely says that having synesthesia helps him remember the notes on the neck of his bass guitar. This is from a video on his Youtube channel:

[SFX Clip: Adam -When I visualize notes and patterns on my bass guitar, they are colored. This fret right here is green, because it’s an F. The fret right next to it is purple, because it’s an E. If I use a different tuning system, the colors change, but only after I’ve relearned where the notes are.]

Adam isn’t alone in using those extra associations to help remember things. In 2004, synesthete Daniel Tammet sat in front of an audience at the Oxford Museum of History and Science and correctly recited the first 22,514 digits of pi.5 Here he is telling David Letterman about it.

[SFX Clip: Daniel - So what I’m doing is I’m visualizing numbers. When you look at a number, when you look at, say, 43, you just see the number 4 and 3, like most people do. But when I look at numbers, you know whatever number it is, I’m seeing colors and shapes and textures. It’s something called synesthesia. Because my brain is working in such a way that I’m looking, and also experiencing color, so it’s two senses combined.]

Richard: When you test synesthetes' memories with standard tests, they indeed do perform extremely high. Basically what synesthesia is doing is hyper connecting or making more connections between two or more different brain areas.

This memory boost might also help explain why this condition has been passed down through thousands of years of human evolution. In prehistoric times, being able to remember which berries are edible and which ones are poisonous could have a pretty big impact on whether you survive or pass on your genes.

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Now, It’s tempting to think of synesthesia as a kind of binary situation: You either have it, or you don’t. But it’s really a matter of degree. On some level…

Richard: We're all synesthetes. We're not consciously aware of all these cross connections happening all the time.

For example, when we talk to someone face to face, we rely on lip reading a lot more than we realize.

Richard: We don't think we do, but the louder it gets, the more we have to look at what a person is saying to understand what it is that they're saying. Even bad ventriloquists can convince us that the dummy is talking and that just shows us how strongly speech and movement are linked.

Richard: Cinema is another example, where we're convinced that the dialogue is coming from the mouths on the screen rather than the speakers that are surrounding us. That's synesthesia, but we never think of it that way because it's so common, whereas if you were to start seeing music, you would think, "Oh, this is really weird. Wow, this is something new." But it's not.

A lot of people get a tingling sensation in the back of their head when they listen to ASMR videos [SFX]. Other people get goosebumps, or feel a chill down their spine when they listen to certain types of music. These could all be considered forms of audio-tactile, or audio-touch synesthesia, since sounds are triggering a physical sensation in your body.

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There’s still a lot about synesthesia that we don’t understand. But what we do know, is that what’s going on inside the brain of a synesthete is a natural extension of what’s happening in all of our brains. And that’s what makes it even more absurd when people accuse synesthetes of lying about their condition.

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David: There's people, when I talk about it, the naysayers that come about are just, you know…“You’re crazy. You're just being weird. This isn't a real thing.” And I'm just like, “Alright, whatever.”

Andie: One time someone was like, ”Oh, what's the color of this word?” And I just hesitated because I was zoning out. And they were like, ”Well you don't have it then. You're making it up.” And I was like, "No, I've had this my whole life."

While the vivid descriptions synesthetes give might sound strange, for the people who have this condition, experiencing life in this way is totally normal.

David: It's just kind of how we exist, for us that are synthese, and...

David: It's like you don't feel your shirt that you're wearing until somebody points it out. You don't realize your glasses are on you until I point that out. And then you're like, “Oh, those are there. Now I feel them.” It's kind of the same thing. I don't realize that I'm feeling these things until I really focus in on it.

No one we talked to said they wished they didn’t have synesthesia. For them, it’s just a part of who they are. Here’s Kylie again, the synesthete who tastes the names of the people she meets.

Kylie: It never really annoys me because I'm just used to it. It's just been my whole life that, words occur as foods in my head. That's just the way I experienced things.

Kylie: It just kind of opens your mind in a way that, is unique and it just makes you think differently about things. So it's a positive experience for me.

Andie: It's called a neurological condition and it's not a disorder. I guess that's what I want people to know. That it actually enhances life for me. And I'm very thankful that I have it.

David: It's not debilitating, and it's not setting me back in any way. It's not something that can be fixed or cured, nor would I want it to be. Because it's just my existence.

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Twenty Thousand Hertz is produced out of the sound design studios of Defacto Sound, the sonic source for the world’s most thoughtful ads, trailers, and games. For a little sonic inspiration, follow Defacto Sound on Instagram.

This episode was written and produced by Lindsay Reddiffer, and me Dallas Taylor, with help from Sam Schneble. It was story edited by Casey Emmerling. It was sound designed and mixed by Joel Boyter and Nick Spradlin.

Thanks to Dr. Richard Cytowic for speaking with us. You can explore his work at cytowic.net. That’s c-y-t-o-w-i-c dot net.

And thanks to everyone who responded to our call for people with synesthesia, including Heather, Rae, Andie Blaine, David Hopper, Kylie Hansen, and Joel Salinas. If you’d like to learn more, be sure to check out Joel’s book, Mirror Touch: A Memoir of Synesthesia and the Secret Life of the Brain.

And as always, you can connect with us on Facebook, Twitter, on our subreddit, or by writing hi at 20k dot org.

Thanks for listening.

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