What do you hear?! Yanny or Laurel pic.twitter.com/jvHhCbMc8I

— Cloe Feldman (@CloeCouture)
May 15, 2018

In the not-too-distant past, the internet has erupted in debate over optical and auditory illusions that mess with our heads and create heated arguments among friends and strangers. Two of the most prominent were “the dress” (optical) and “Yanny/Laurel” (auditory) controversies. These discussions have illuminated a surprising truth about perception: Even something as seemingly objective as a sight or sound is actually subjective.

How could it be that you and your friend are looking at the same picture, but one of you sees a blue-and-black dress while the other sees a gold-and-white one? How can you two listen to the same audio recording and one of you hears the word “Yanny” while the other hears “Laurel”? Recent research helps explain the science behind these polarizing viral trends.

The Dress: Why Do We See What We See?

First posted in 2015, an amateur photo sparked controversy on the internet: People couldn’t agree on the color of the dress the picture showed. It was either obviously white and gold or definitely black and blue. Poor image quality and lack of context created ambiguous conditions, but there’s more to the story.

According to the American Academy of Ophthalmology (AAO), objects reflect different wavelengths of light that our brains see as color. Inside our eyes, the retina has millions of rods and cones, which detect and respond to light. Your past experiences also influence your perception of color, even in different conditions. The AAO gave an example of a lemon: even under red light, you would still perceive it as yellow, because you know lemons are yellow. The dress backs up this theory, called color constancy. According to The New York Times, research published in Current Biology supports the color constancy hypothesis and helps explain the science of visual perception.

One study concluded that the confusion was caused by the ambiguity of the color blue and people’s inability to discern blue objects from blue lighting. Another blames the fact that the pixels of the dress matched the shades of blue and yellow that we see in natural daylight. The different ways people perceive natural light could have caused some to see white/gold versus blue/black. Scientists found that some people favor cool-toned lighting, like blue sky, and perceived a white/gold dress; others, who favor warm lighting, saw a blue/black dress. A third group saw blue/brown, as reported by The New York Times.

Yanny vs. Laurel: Why Do We Hear What We Hear?

In May 2018, an audio clip of a single word reignited the passionate dress debate and joined the list of perplexing viral trends. Some people heard the sound “Yanny” while others heard “Laurel,” and there wasn’t a clear reason for the difference.

Why do people hear the same audio clip differently? Just like the dress, a lack of context and low-quality recording created ambiguity. Plus, listening to the recording on different devices (headphones, tablets, speakers, etc.) can distort the sound.

University of Arizona professor Brad Story analyzed a waveform image of the viral recording and compared it to recordings of himself saying Yanny and Laurel. This acoustic analysis helped explain the confusion. He determined that the two words have similar patterns, with the resonance (strong and deep in tone) of parts of the word Laurel matching the resonance of parts of Yanny. This similarity can lead to a mix-up in the way we hear it, especially without any context clues, reported CNN.

“If you have a low quality of recording, it’s not surprising some people would confuse the second and third resonances flipped around, and hear Yanny instead of Laurel,” Story told CNN.

Could it be that your ears are just different from your neighbor’s? There are mechanics of the ears that influence the way we each hear subtle sounds. Gizmodo explained that our outer ears focus sounds into our ear canals; therefore, differently shaped ears could change the way you hear different pitches or sound frequencies. Since Yanny and Laurel are made up of several frequencies, there is room for interpretation.

We’re All Right, Even When We’re Wrong

No matter the facts, each person’s perception can vary based on many factors. The differences could be technical (what kind of device you’re using), physical (such as the number of rods in your eyes or the shape of your ears), and psychological (assumptions you make to fill in the blanks based on past experience). Even after the truth is revealed — it was a black and blue dress, after all — we can’t always override what our eyes and ears tell us. Ambiguous conditions can leave things open to interpretation and create optical or auditory illusions, which, in turn, are bound to create debates.