Neuromarketer and best-selling author Martin Lindstrom, who uses the tools of neuroscience to help businesses better understand their customers, recently partnered with music and sound design firm Elias Arts to identify the "most addictive sounds in the world."
Though the researchers referred to the sounds as "addictive," they mean that in the sense of generating a response, not that people are addicted to the sounds themselves.
"We have all those top 10s of everything, but most top 10s are based on the visual sense," he said. "What we realized in another study is the most prominent sense we have [when we see a commercial] is not the sense of sight or smell, but the sense of sound."
Building on previously published neuroscience studies, the researchers wired up 50 volunteers and monitored their pupil, brainwave and facial muscle activity as they listened to 50 everyday and culturally significant sounds.
They learned that it's not necessarily the sounds of nature that are most "addicting." The beeps, jingles and ditties of commerce beat out several familiar sounds of everyday life.
On the list of overall sounds (both branded and non-branded), the sound of a baby giggling grabbed the number one spot, but chip manufacturer Intel's distinctive chime came in at number two. The sound of a vibrating cell phone ranked third.
Among branded sounds, Intel's tune was followed by those of National Geographic and MTV, respectively. Other non-branded sounds included a steak sizzling, a cigarette being lit and inhaled and "Hail to the Chief."
Lindstrom said brainwave activity, pupil dilation and muscle movements on their own can indicate both positive and negative reactions. To determine the dimension of the responses, he said the researchers looked at the contrast and balance of all three factors.
But he emphasized that the volunteers weren't responding to the structures of the sounds, but what they mean in a greater social context.
"It's not the sound itself, but the consequence of the sound," he said. A laughing (or crying) baby elicits a maternal protection mechanism, he continued, a buzzing cell phone prompts a pick-up, a sizzling steak means a solid meal is on the way.
For advertisers and consumers, he said the research indicates a "whole new battleground" of multi-sensory advertising.
A McDonald's-sponsored ring-tone might not just include its familiar jingle, but also the faint sound of steak on the grill, he suggested.
Lindstrom also said that sometimes the sound from one category generates a craving in another category. For example, given the links between tobacco and beverages, the sound of a cigarette being lit could be used in an ad for alcohol.
But he added that though sound is more intuitive for people, the field is still quite young.
"It will be a long time before it will be so prominent," he said.
Barbara Shinn-Cunningham, an auditory neuroscientist at Boston University, said that though the sounds identified by the study are extremely meaningful, with the exception of the giggling baby, most are not inherently addictive.
"They're identifiable. They brain responds to repetition. Our brains are good at picking out patterns that repeat. We've evolved to do that," she said.
She said that if she chose an arbitrary sound, as long as it was clear and distinctive, and then played it 50 times a day for the next five years (as many of the branded sounds have been), it would become attention-grabbing.
Of most sounds on the list, she said, "I don't think they're so much addictive because of their acoustic properties, but because of their ubiquity."
Still she said that there is neurophysiological evidence showing that brain is hardwired to notice certain kinds of sounds.
For example, the abrupt, jarring sound of a slamming door could prompt cells in a person's brain stem to fire even before that person was conscious of it, she said. For early humans, that kind of sound could have meant it's time to run for the hills.
She also said that studies have demonstrated the existence of a so-called "cocktail party effect."
"At a party, if you hear your name in the background, even if you're not paying attention, that's something that will draw your attention involuntarily," she said. "Your brain is so exposed to your name and it's tremendously important to you, so it encodes that so you respond to it."
That's one addictive sound that isn't likely to pop up in a commercial anytime soon, but for a complete list of the other most addictive sounds, click on to the next page.
1. Baby giggle
2. Intel chime
3. Vibrating phone
4. ATM/cash register
5. National Geographic theme
6. MTV theme
7. T-Mobile ringtone
8. McDonald's jingle
9. "Star Spangled Banner"
10. State Farm jingle
1. Intel chime
2. National Geographic theme
3. MTV theme
4. T-Mobile ringtone
5. McDonald's jingle
7. State Farm jingle
8. AT&T ringtone
9. Home Depot jingle
10 Palm Treo ringtone
1. Baby giggle
2. Vibrating phone
3. ATM / cash register
4. "Star Spangled Banner"
5. Sizzling steak
6. "Hail to the Chief"
7. Cigarette light and inhale
8. "Wedding March"
9. "Wish Upon a Star"
10. "Late Night with David Letterman" theme