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Sat July 5, 2014
Brain Candy

What Does Cold Sound Like? See If Your Ear Can Tell Temperature

Originally published on Mon July 7, 2014 9:22 am

Can you hear the difference between hot and cold?

A British "sensory branding company" called Condiment Junkie wanted to know the answer. They specialize in sound design for all sorts of advertisements. Now they're taking a look at how they might use sound design to make better beverage ads. Take the sound of water pouring in this Twinings Tea commercial.

The marketers wanted to know: Would it be possible to make that noise itself more appealing? Can people hear the difference between a hot cup of tea being poured and, say, a cold beer? And is it possible to make a hot drink sound hotter or a cold drink sound more refreshing?

So they did an experiment. They played sounds of hot and cold water being poured into glasses and asked people to guess: hot or cold? The results were kind of insane. Ninety-six percent of people can tell the difference between hot and cold, just by the sound.

So, can you hear the difference?

Glass 1

Glass 2

Glass 1, as 80 percent of you were able to tell, was cold.

Glass 2, as more than 90 percent of you detected, was hot.

Condiment Junkie, the sensory branding company behind these sounds, is trying to isolate exactly what it is about the sound of hot or cold water that tips people off to its temperature. And the answer isn't the difference between cups and mugs, as some commenters guessed — Glass 1 and Glass 2 were identical containers.

Scientists have long known that cold water is more viscous than hot water, because the molecules are wiggling less rapidly, so they are effectively stickier. How viscous a liquid is affects how it pours, and therefore how it sounds. Scott King, one of the founders of Condiment Junkie, says bubbliness is also a factor.

"There tends to be more bubbling in a liquid that's hot," he explains. "As you have more bubbling, you tend to get higher frequency sounds from it."

You can hear that effect in the sound of Glass 2, above. It begins and ends with a high-pitched ringing sound. The question for Condiment Junkie is whether it's possible to make liquid sound hotter or colder by, for example, accentuating that ringing.

Copyright 2014 NPR. To see more, visit http://www.npr.org/.

Transcript

KELLY MCEVERS, HOST:

A marketing firm in England recently set out to gather data that would help make better advertisements for drinks, like tea.

(SOUNDBITE OF COMMERCIAL)

UNIDENTIFIED ACTRESS: Twinings Infusions are all sourced from nature. From nettle and peppermint, to strawberry and mango.

MCEVERS: The marketing firm called "Condiment Junkie" specializes in sound design for ads like this one. They wanted to know, can people hear the difference between the pouring of a hot cup of tea and a cold glass of lemonade. So they did an experiment. They played sounds of hot and cold water being poured into glasses and asked people to guess - hot or cold? Here's one of the samples they used.

(SOUNDBITE OF WATER POURING)

MCEVERS: And here's another.

(SOUNDBITE OF WATER POURING)

MCEVERS: The results were kind of insane. Ninety-six percent of people can tell the difference between hot and cold pours just by the sound.

(SOUNDBITE OF WATER POURING)

MCEVERS: Can you hear the difference? If you can, go to our website NPR.org, and tell us which sound is hot and which sound is cold. You'll find recordings of the sounds, plus an online poll on our homepage. And tune in tomorrow to find out if you were right about this refreshing glass of ice water.

(SOUNDBITE OF WATER POURING)

MCEVERS: Oh, wait. Maybe it was this one.

(SOUNDBITE OF WATER POURING) Transcript provided by NPR, Copyright NPR.