Crunch, Crackle, and Pop

Support for this show comes from Pure Leaf Iced Tea.

When you find yourself in the afternoon slump, you need the right thing to make you bounce back.

You need Pure Leaf Iced Tea.

It's real brewed tea made in a variety of bold flavors with just the right amount of naturally occurring caffeine.

You're left feeling refreshed and revitalized, so you can be ready to take on what's next.

The next time you need to hit the reset button, grab a Pure Leaf Iced Tea.

Time for a tea break?

Time for a Pure Leaf.

Support for this show comes from Pure Leaf Iced Tea.

When you find yourself in the afternoon slump, you need the right thing to make you bounce back.

You need Pure Leaf Iced Tea.

It's real brewed tea made in a variety of bold flavors with just the right amount of naturally occurring caffeine.

You're left feeling refreshed and revitalized, so you can be ready to take on what's next.

The next time you need to hit the reset button, grab a Pure Leaf Iced Tea.

Time for a tea break, time for a pure leaf.

So I certainly think that sound is the last sense that anyone who thinks about food thinks about.

It's always sort of smell and taste first, and maybe the colour of food and maybe the textures.

Sound is the one that's left out by sort of food scientists and the general public alike.

That's right.

We've talked on Gastropod about how sight and smell influence the way you taste your food.

But this week we're all about sound, the forgotten flavor.

This is part two of two episodes.

You've already heard about how sound might help us find insects in the field and diagnose sick chickens.

Now you'll hear about how sound might make your toffee taste sweeter.

And your Pringles crispier.

I'm Nicola Twilley.

And I'm Cynthia Graeber.

Stay tuned for the secrets of sonic seasoning.

The go-to guy for sound and food is.

Professor Charles Spence, I'm head of the Crossmodal Research Laboratory here at Oxford University.

You might be wondering just what cross-modal means.

So we've kind of broken the brain down or perception down into each of the senses but kind of a growing area of research is highlighting just how much the senses talk to each other in our mind and how if you change one sense it can have kind of a profound impact on what you experience in another.

So for example we might find that if I change the smell as you're looking at something, it might change how attractive it looks visually.

If I change what you hear it might change what you taste.

If I change what you taste, it might change what you feel.

So, all the senses are connected much more.

That's kind of the cross-modal bit.

Charles started out working on how to make car dashboards safer by making sure all the different inputs work together to help drivers notice only what they need to.

There's the alarm sounds and the lights and even tactile sensations from the steering wheel.

But food is one of life's most multi-sensory experiences, so it makes sense to study how all the different elements-sight, touch, taste, smell, and of course, sound, how they all combine to create the experience of eating or drinking.

Charles first turned his attention to figuring out food while he was working on a completely different project.

He was collaborating with a big personal care company to try to figure out how to trick the brain into thinking clothes felt even softer against your skin after applying their particular lotion.

He was using a weird phenomenon called the parchment skin illusion.

You can try it easily at home.

Rub your hands together and then put in earplugs and rub them together again.

Want to try it right now?

So they should feel a little softer when you have the earplugs in.

The way your brain works, it combines the feeling with the sound to create the overall sensation.

And when the sound your hands make is muffled, your brain decides, well, that must mean there's less friction, and so your hands must be smoother.

And it crossed Charles's mind, why wouldn't this sort of brain trick work with food?

So what really changed, I think, about 2004 when we did a kind of sonic crisp experiment where we had people biting into potato chips and then we changed the sound as they were biting into the potato chips and we could show that we could make them crispier or fresher simply by changing the sound of the crunch.

He recorded the sounds of Pringles crunching as you eat them.

Then he recruited volunteers to eat 200 Pringles.

For science, of course.

They were wearing headphones and as they crunched, Charles would play back either an amplified crunch or a muffled crunch.

Got the equipment set up and found that we could make about a 15 to 20 percent change in people's experience of Christmas and freshness simply by changing the sound in real time.

He actually won an Ig Nobel for this in 2008.

That's the annual prize for research that makes people laugh and then think.

But it is in fact good science.

Other researchers even replicated it.

Scientists in northern Italy tried the same experiment out with apples.

They showed they could make the apples taste fresher by boosting the sound of the crunch.

And then there's a twist.

So in the kind of the fun party version, colleagues in Japan and also in the Netherlands who would get you to bite into a food in time with a metronome.

So you're kind of crunch, crunch, crunch, and you're crunching in time with the metronome you're hearing in the background.

And each time you crunch, they can then synchronize a sound to your biting action.

So maybe you go crunch, crunch, crunch, and they play you a crunch, crunch, crunch sound.

And then the next time they play the sound of breaking glass,

and suddenly they say, you know, people's jaw just kind of freezes up.

It's like they just people just cannot keep crunching because that sound is so aversive and it's sort of telling you you're going to do yourself damage.

I am in pain just thinking about this experiment.

Right.

But you know the thing I was curious about was why.

Why would our brains prefer more crunch?

I mean there might be a sort of evolutionary story about sort of a crispy and crunchy being associated with fresher produce.

And that would be something that we might have you know wanted to look out for.

So that might have been an evolutionary advantage.

Fresher food in nature is crispier but there also might be a learned response.

Our ancestors might have learned to like the crackle of skin and fat from meat fresh off the fire.

It might also be that

our brain might find it hard to discriminate the fat content in some foods.

And maybe then there's kind of a correlation between kind of how much a food crackles or crunches or how crispy it is for sort of for dry food products and the fat content.

And maybe our our brain has learnt that

it likes fat, even if we don't think we should.

Something in our brain likes it.

And maybe that's correlated with kind of the louder crunch.

And then never discount sheer novelty value.

Kind of the more stimulating, maybe the better.

So the more senses our food engages, perhaps the more immersive or enjoyable the overall experience can be.

Crunchiness and crispiness are not the only sound cues we get when we eat.

There's creaminess as well.

Charles has a colleague in the Netherlands called George van Aiken who tested this out with a really fun coffee experiment.

And he's got this wonderful example of the coffee where he says just if you take a cup of black coffee and then take a mouthful and then sort of run your tongue across kind of the underside of your upper palate, the roof of your mouth.

And if you do that and it's quieter outside you can sort of hear something.

And then he says okay add a little bit of cream to your coffee and then repeat.

take a mouthful of that creamy coffee,

roll it around your mouth and then take your tongue and again, rub your upper palate, the roof of your mouth, and you can sort of hear a difference that kind of as the cream, I guess, sort of coats the surface of your tongue and your upper palate, then that kind of changes the friction or the interaction between tongue and palate, and that leads to a change in the sound.

You can try this one at home, too.

It does work.

Charles isn't sure there's an application for it.

Because it's much harder to fake than crisp crunching.

It's really like a sound that is physically inside your head.

But if it did work, it it would be a great way to add cream to your coffee, even if you happen to have run out.

So now we've gone through crunchy and creamy, and now another fun food C-word, carbonation.

We're going to read lots of the wine press, and there you'll find in print some sort of wine writers talking that they can tell the quality of a wine by the sound it makes when it's poured from the bottle, that they can tell a quality champagne by the sound of the bubbles,

that they can tell champagne from Prosecco, from other sparkling wines by the bubbles they make.

And we want to know, is that true?

Are they making it up?

Can only experts do that?

Do you have to, you know, drink so many bottles in order to be able to tell by sound alone what you're drinking?

So Charles tested them.

He recorded the sound of pouring champagne

and then Prosecco

and then soda water

all into the same type of glass.

And he asked people to guess what drink it was based on the sound of the pouring alone.

And there we find that people are better than chance.

They're not perfect, but they are better than chance in discriminating what kind of drink it is that they are hearing being poured at those different size of the bubbles, say between soda, water and champagne, really do sound different.

And then so whenever you hear a drink being poured, your brain is probably picking up the sound of those bubbles and setting an expectation about what you're about to taste that can then change the experience when you actually taste something.

Charles says you can't make people think something's fizzy if it isn't fizzy at all.

It's kind of ramping up the sensation that's already there.

But he and the Swiss chef, Denis Martin, did create a a dish I am dying to try.

It's a frozen gin and tonic and they added the sound of bubbles.

But the one thing that's missing there is the sound that's been kind of sort of frozen out.

So that was just kind of a nice way to sort of bring the sound back to the experience.

And because of the change of, because then you're eating kind of a solid gin and tonic, your brain is in a sort of slightly different place from having a still liquid gin and tonic, if you will.

This is kind of a new format, a new experience for you.

You've never had gin and tonic kind of frozen in that way before.

That maybe bringing bringing the sound in can give you a bit of that missing sense.

Speaking of frozen, the other thing that Charles has been testing lately is the sound of temperature.

So, here's a test: can you tell the temperature of these two drinks just based on the sound they make while they're being poured?

Well, can you?

The first one you heard, that was cold water, and the second one was hot.

Did you get it right?

Let us know.

Charles says you should have.

It seems to be that as a liquid changes its temperature, it changes its viscosity.

And that change in viscosity you can hear when a drink is poured into a receptacle, a glass, has like a change in pitch.

In any way, for us, I just read about this sort of the sound of temperature, and maybe I should have known it existed given all the work on the crunch we did, but I read about it and I just thought, that can't be true.

But when you think about it, based on his previous research, it does make sense.

And it's such a sort of thing that's there.

Every day we pour a drink or we pour ourselves a hot bath.

It's there all the time, but we kind of never think about it because we're always concentrating on what we see instead.

And it's any way you kind of isolate those sounds.

You can really highlight to people how much information there is and we can tell and then think about how you can use that information to sort of change experiences, change expectations as a result.

Imagine the ways you could screw with diners.

Yep, that's where Charles went with this too.

And then we might play those sounds back maybe in the context of a dark dining scenario.

So you're in a restaurant, it's completely dark, the waiter comes to your table, pours you a drink, doesn't say anything about it.

But somehow we put the idea in your mind, the expectation it's going to be very hot.

And then when you put it to your lips and it's suddenly cold, you'll be surprised, you'll be shocked.

But you probably won't know quite why.

You should be shocked because no one told you anything about it.

Avoiding your unfinished home projects because you're not sure where to start?

Thumbtack knows homes, so you don't have to.

Don't know the difference between matte paint finish and satin, or what that clunking sound from your dryer is?

With Thumbtack, you don't have to be a home pro.

You just have to hire one.

You can hire top-rated pros, see price estimates, and read reviews all on the app.

Download today.

Bundle and safe with Expedia.

You were made to follow your favorite band and

from the front row, we were made to quietly save you more.

Expedia.

Made to travel.

Savings vary and subject to availability.

Light-inclusive packages are at all protected.

So far, we've talked about the sound of food very literally.

The crunching and the popping and the pouring and so on.

But Charles has also done research into the idea of audio cues.

The idea that certain sounds or music can prime us in a way that changes our experience of a particular food or drink.

This whole thing came out of an evening event he had planned with the British chef Heston Blumenthal.

So there's 120 people who paid some money for an evening.

They're expecting some food from Heston and some experimentation and some science.

And we kind of left it a little bit to the last minute.

Didn't know quite what to do with people.

And so they thought, oh, hell, what the hell?

And so Heston brought up a kind of a van full of oysters.

And then we had the audience kind of split into two.

And we said, okay, let's just play different sounds.

So we gave them oysters.

And half the audience listened to the sounds of the sea.

Kind of the seagulls flying overhead and the waves crashing on the beach.

The other half listened to sort of farmyard chickens clucking away.

And then people also got this bacon and egg ice cream.

And again, half the people heard, in that case, the sound of sizzling bacon in the pan.

And the other half of people who were eating the ice cream heard the sounds of the farmyard chickens.

I never think it was going to work, but anyway, we had to do something.

So that's what we did.

And then it turned out it did work.

It worked beautifully.

That those sounds coming out of the tanoi overhead really did change people's rating of both the oysters and of the bacon and egg ice cream.

They rated the seafood as more pleasant while listening to the sound of the sea.

And when we asked people to say, How bacony or how eggy does that ice cream taste to you?

Then those who are listening to the sizzling bacon sound got a more intense bacon-y note from the ice cream.

Those who are listening to the farmyard chickens rated the eggy sensations as significantly stronger or greater.

And out of that came one of the most famous dishes of the 21st century.

the sound of the sea.

It's a seafood dish that comes to your table with sand and foam and seaweed.

It's a whole seascape on your plate.

And in the other hand, the waiter will bring kind of a cone shell out of which dribble some little earbuds and he'll recommend in his best french accent that you know you put the put the earbuds in before you start the food and when you do that you will hear kind of specially created soundscape with not just the right number of seagulls and just frequent enough waves crashing on the beach that almost it sets the scene but doesn't overpower the dinox idea so that everyone can almost in a way put their own memories of being at the sea onto that kind of stripped back ordinary backdrop.

And it's kind of remarkable to see people in the restaurant where you have a beginning for like once in a lifetime real and it's so exciting and they'll be talking and chatted and excited and and then when the headphones go in there's silence at the table no one's talking everyone's attention is squarely focused on what they're eating and it's linked to what they're hearing and for sort of five or ten minutes they're very much in a much more mindful much more attentive relation with their food and I think that's also part of why the dish works so well it wouldn't work for everything if you had a 20 course tasting menu and you you had earphones on all the time, that definitely wouldn't work.

But for one course to really kind of make you mindful and attentive to what you're eating, putting those earbuds in really helps.

A dinner at Heston Blumenthal's restaurant costs an arm and a leg, but Charles thinks this idea could spread.

And also the challenge is to say, okay, could we turn that idea or insight from the chef bringing you the technology to the table for the once-in-a-lifetime experience to saying, well, hey, most of us have got these smartphones and other devices in our pockets all the time that are very technically advanced, advanced, that currently are mostly distracting us from what we're eating.

How can we kind of reposition that technology in order to give everyone the opportunity to either digitally season their food to make it sweeter or more bitter or to add the right sort of ethnic or authentic or seaside sounds, whatever it might be, to enhance the experience?

It's not just about getting in your earbuds, though.

I mean, food is social, and I know most people don't want to be locked off from their dining companions, no matter how much it improves the flavor.

At least not usually.

Perhaps for some families this could be perfect for next Thanksgiving.

But for group dinners out, Charles has a different idea.

I mean we are working with these hyper-directional loudspeakers so that one table could hear one soundscape, but the next table along hears something completely different.

So you've got very directed sound.

That could be one way of doing it.

So if one table orders this wine, the next table orders that wine, you could have the music that would match each table's, that would not bleed into the other person's experience.

Or it may be we're also working on glasses that

imagine a glass that as you pick it up and tilt it to your lips, only then do you hear the sound of the music playing, and you hear the sound of the music playing from inside the glass, from the surface of the liquid.

We have the technical means to do that now.

Glasses that are also speakers sound nuts, but it'd be perfectly synchronized to every sip.

Which Charles guesses would make the effect even stronger, even more likely to trick our brains.

So, we've gone from the sound food makes in your mouth to the idea of matching sounds and foods by topic, like eggs with chicken or fish with seagulls.

But Charles has also looked into the more abstract qualities of sound.

Turns out that the pitch and the volume and the tempo, they all affect our experience of food, both in terms of its flavor and how we eat it.

Say in the restaurant or bar setting, what we hear does influence us.

It influences both our behavior in terms of maybe what we choose to order or to buy, how quickly

we end up bringing the fork to our lips or the glass to our mouths.

And it also affects our perception of what we're eating or drinking, both in terms of how expensive we think maybe the wine is, it affects how sort of authentically ethnic the cuisine appears to be.

If the music is matched, that helps.

This is something that quite a few scientists have looked at over the past decade or so.

There's a guy called Adrian North at Harriet Watt University in Edinburgh.

He's shown that people spend 10%

more when classical music is playing in a restaurant.

His guess is that because people think classical music is upscale, that association transfers onto the food, making you willing to spend more.

And how loud the music is also makes a difference.

Loud music has been shown to boost soft drink sales and speed up how fast people eat.

And the louder the background noise or music is, the less strong all the tastes seem, except for umami, the savory taste.

Which is one major reason why airline food is so bland and why ordering an umami-rich bloody Mary suddenly makes so much sense when you're on a plane.

I mean, the sound in an aircraft cabin is about 90 decibels.

The other thing scientists have shown is that, unsurprisingly, fast-paced music makes people eat faster, and slow makes them eat slower.

So, music may seem like just a background thing, but it does turn out that the tempo and the volume and even the style of music really do make a difference to your dining experience.

But Charles has also been teasing out something even more elusive, the relationship between pitch and taste.

What we're finding at the moment is you can actually, certain music, certain certain musical parameters, certain instruments or musical pitches are associated with certain tastes and if you know the taste of or the music or the sounds that match sweetness, the sounds that match sourness, if you know those sounds you can then look for pieces of music that have already been recorded or create special musical soundscapes that are sour, bitter, in some sense sweet and what you find is when you play those sounds to the diners in the restaurant or in the lab that you can add about a sort of five to ten percent say, sweetness.

So, suppose you want to make your ice cream taste sweeter without adding more sugar.

I'm so looking for something that's sort of higher in pitch and maybe sort of something like tinkling pianos or wind chimes.

We're working with composers and sound designers to actually make specific sounds that have all the parameters just right.

But for those at home, it could be we use something like Mike Oldfield's tubular bells, if you remember him from a decade or two ago.

Or if you like classical, then it could be some of the tracks from a sort of Carnival of the Animals.

When it comes to bringing out bitterness, for those who like the coffee, bitter or dark chocolate, then we're looking at sort of lower pitch and brassi, so we might use Guciano Pavarotti singing Nesandorma, that's got some, that works quite well,

or Camina Barana.

It all goes back to that cross-modal thing Charles talked about earlier.

This is the perfect example of how our senses influence each other.

Those sounds that seem sweet, the high tinkling piano notes, for example, they make your brain pay more attention to the sweet tastes that are already in your ice cream or whatever you're eating.

Charles hasn't figured out how to make this work for every taste yet.

We struggle a little bit to find the sound of salty.

We struggle a lot, I should say.

Sweet, bitter, sour, dead easy now, I think.

We've got music that we're playing to people around the world and

80-90% of them all get it.

Yeah, that's definitely sweet.

Yep, that's definitely sour.

Of course, it's got to be bitter salty we struggle with and why should bitter and sweet be so easy or easier than the other tastes well maybe it's because when we're at birth if we're no matter if you're a chimpanzee a rat a human if somebody puts a bitter taste on a newborn's tongue the tongue will immediately go out and down as you try and eject that potentially poisonous food you go

get rid of it If you put a sweet taste on a newborn chimp, rat, human baby's tongue, then the tongue will go out and and up

as you try and lick the goodness, you try and ingest kind of the calories.

So we're all born sticking our tongues upwards to sweet tastes, our tongues downwards to bitter tastes.

That's kind of around us in the environment.

And maybe our brains just pick up on that correlation.

And if you think about the sort of, you make slightly different sounds with your tongue up and down, kind of,

as best I can demonstrate it.

And our brain picks up on those kind of correlations in the world.

The fact that sweet is normally associated with a different sound than bitter.

And if you then play those sounds back, it can sort of change the expectations and hence the experience of taste for somebody, even as adults.

Let me see, okay.

I wish I could see your face right now.

Maybe it's better that you can't.

The joys of radio.

As you can probably tell, this kind of research is in its really early days.

I think there are

more musical parameters to be uncovered, more tastes and flavours to be mapped in terms of kind of the music that they link to.

So we we kind of started in a way the easy stuff, taste, because we can more or less agree there are five tastes, bitter, sweet, salty, sour, umami, that's it.

So if you've got a music for each of those, you've kind of covered the world of straight real taste.

When it comes to flavours, then you've got sort of citrus and meaty and fruity and floral and burnt and creamy.

And no one can quite agree how many different categories of aroma or flavour there are.

And that's a huge palette then to study and work on.

That'll keep us going for quite a long time.

We're also very interested in the kind of cross-cultural question that a lot of the work we do is based in Oxford or sometimes online with people in North America and in Europe.

But the music that we create to match the taste, would that work if I played it to somebody in India or in Japan or Korea or Colombia where they have very different kind of musical repertoires?

Is it universal or is it culture specific or which parts of this kind of music mapping to taste and flavor are universal and which culture specific?

That's a big question on when we are starting to probe and showing that some of the soundtracks that have been created by a European ear are nevertheless interpretable and understandable by an Indian individual's ear.

Part of understanding whether these multi-sensory responses really are universal is figuring out what's going on in the brain while they're happening.

Obviously, that brain question, whereabouts in the brain is the sound of music and taste and flavour interacting.

That would be useful information to us.

That will help kind of unpick the mechanism by which this music, which has nothing really to do with the food, nevertheless influences it.

So there's lots still to find out, but there are already a lot of people experimenting with applying Charles's findings in the real world.

He's worked with airlines to create soundtracks to help boost flavors to make airplane food taste better.

He's worked with hospitals to try to create environments that encourage elderly and sick patients to eat more.

And he's even helping figure out whether these kinds of tricks could be used by food companies to cut sugar and salt.

But perhaps his most useful contribution to human happiness is helping craft the perfect soundtrack for whiskey.

You know that we here at Gastropod are big whiskey fans.

Nikki, tell us what we should be listening to while we drink.

Well, remember Sam Bompas from our cocktail episode?

You mean the guy who peered into our souls and gave us our perfect cocktail?

How could I forget?

So he partnered with Charles Spence and Johnny Walker to actually build a flavor organ, like a church organ, but specifically tuned to the pitches that Charles has shown boost flavor and they composed a piece of music for their organ that takes you through all the flavors in your glass from the sweet notes to the more bitter earthy ones and the savory notes that are in a really good whiskey too

That sounds incredibly cool.

I would love to have an organ playing while I was sipping some scotch.

It was.

They brought the organ to New York last November and I got to try it.

And it really did help me pull out all the different flavors in the whiskey in a way that I don't normally do.

Okay, now I'm jealous, and Tim will be too.

But really, you don't need to build an entirely new musical instrument to play with sound.

You just need to pay attention.

There's sound everywhere.

And in a way, that's what's really interesting here.

It's like in our last episode, we spoke to scientists who are trying to take advantage of sound to help farmers, because sound is kind of ignored, but it's a crucial source of information when it comes to food.

Thank you this week to Charles Spence and his grad student, Ichuan Chen, who helped out with the recording.

Also, don't forget you should like us on Facebook, follow us on Twitter at GastroPodcast, and donate to the show on our website.

A huge thanks to all of you who have given already.

We are so touched and grateful and happy that you choose to support us.

Thank you.

Till next time.