Questions: Why do your eardrums move when your eyes move?

I figured I was just getting old.

My hearing has been getting worse, bad enough that I finally went to the doctor on Tuesday.

She, along with a nurse, managed to extract two quarter-sized pieces of what looked like fungal felt, one from each ear. She prescribed some antibiotics to see if the swelling would go down.

My hearing and balance improved immediately.

Which prompted a question that Ed Yong of The Atlantic has ventured to answer: Why do eardrums move when your eyeballs move?

As your eyes flitted right, both eardrums bulged to the left, one inward and one outward. They then bounced back and forth a few times, before coming to a halt. When you looked left, they bulged to the right, and oscillated again.

These wobbles happen every time you move your eyes, whether or not there’s external noise. The bigger the movement, the bigger the wobble. But no one knows why they happen. And until Jennifer Groh, from Duke University, discovered them, no one even knew that they happened at all.

Groh has long been interested in how the brain connects information from our eyes and ears. In a loud party, for example, we automatically read the lips of our conversational partners to interpret any unintelligible sounds. For that to work, the brain has to align visual and auditory information in space, so it knows that those sounds are coming from those lips. And that’s easier said than done, because our ears are obviously fixed on our heads but our eyes are constantly moving. They flit all over the space in front of us, roughly three times a second. Every such movement changes the spatial relationships between what we see and what we hear. So how does the brain unite those streams of information? And where?

“Historically, people have thought that information enters the ear and the eye separately, and that eventually it’s combined,” says Nina Kraus from Northwestern University. But Groh’s experiment, she says, suggests that this act of combination happens much earlier. The eardrum, after all, is responsible for converting vibrations in the air around us into vibrations in the liquid within our heads. It’s where hearing effectively begins. And if it wobbles as our eyes shift, then this suggests that vision might affect hearing “at the earliest possible point,” says Kraus.

Kurtis Gruters and David Murphy, two members of Groh’s team, detected the wobbling eardrums in the simplest possible way. They stuck microphones in the ears of several volunteers, and asked them to look at different targets. As their eyes moved, so did their eardrums. Like actual tiny drums, these vibrating membranes created small sounds, which the microphones could detect. That’s how the team showed that the eardrum oscillations match the direction and strength of the eyes’ movements.

They also found that the eardrums start to wobble about 10 milliseconds before the eyes. This suggest that the ears aren’t reacting to what’s happening in the eyes. Instead, Groh says, “the brain is saying: I am about to move the eyes; ears, get ready.”

Barbara Shinn-Cunningham, from Boston University, also studies the neuroscience of hearing, and she is more circumspect. “It is a very interesting and previously unknown phenomenon, which may turn out to be incredibly important,” she says, “But so far, there is no evidence it is. We just don’t yet know why it happens or what it means.”

Does USDA overrule its own veterinarians on the slaughterhouse floor? Live testimony today

Today’s The USA Today (I never tire of using that) reports that Dean Wyatt, a supervisory veterinarian at the U.S. Department of Agriculture’s Food Safety and Inspection Service will tell a congressional hearing today that USDA superiors failed to act on reports of illegal and unsafe slaughterhouse practices, letting suspect operations continue despite public health risks.

The story says Wyatt will detail instances in which he and other inspectors were overruled when citing slaughterhouses for violations such as shocking and butchering days-old calves that were too weak or sick to stand. He also describes being threatened with transfer or demotion after citing a plant for butchering conscious pigs, despite rules that they first be stunned and unconscious.

In 2008 and early 2009, Wyatt ordered suspensions in operations three times at Bushway Packing Inc., in Grand Isle, VT. Among other things, he found downed calves being dragged through pens to slaughter — a violation because contact with excrement can contaminate animals. In each case, he says, managers overruled him and allowed the plant to keep running.

Bushway subsequently made headlines last fall when the Humane Society of the United States filmed undercover video of workers hitting and using electric prods to move calves. The plant was shut down.

CBS Radio called about 5 a.m. for comment – they’re so polite, they always e-mail first to see if I’m awake so they don’t wake the household. As soon as I said, yeah, let’s do it, 1-year-old Sorenne awoke so I missed the first call to change a diaper and provide 8 ounces of milk. But, the reporter at CBS in N.Y. agreed it was a good call, kid first, then radio soundbites, in which I said something along the lines of, I don’t know anything about the specifics of these cases, but the best slaughterhouses won’t be held hostage by a dude with a video camera, and will get way, way out in front of the minimal standards required by USDA. Maybe it’s too early and I’m still dreaming.