Dogs and cats can turn their ears toward a sound, but most people cannot. We still have small muscles around our ears, but many people thought they were useless.

In 2020, scientists in Germany put small sensors near people's ears. When people listened carefully to a sound, the muscles on that side became active. The ears did not really move, but the muscles were still working.

Many animals turn their ears toward interesting sounds, but humans lost this ability millions of years ago. The muscles around our ears have therefore been called vestigial, meaning they have lost their original purpose. In 2020, however, Strauss and his team in Germany recorded tiny electrical signals from these muscles.

When participants paid attention to sounds from a certain direction, the muscles on that side became more active. In 2025, the same group found that one muscle above the ear became especially active when listening was very difficult, such as when several voices were talking at once. The ears do not visibly move, but researchers hope this activity could someday help control smarter hearing aids.

Cats and dogs swivel their ears toward interesting sounds, but humans are thought to have lost this pinna-orienting ability around 25 million years ago, leaving the small muscles around our ears as textbook examples of vestigial structures. In 2020, Strauss and colleagues at Saarland University placed surface electrodes on these muscles and ran two experiments.

In one, unexpected sounds such as a baby crying came from different directions while participants read; in the other, participants listened to one story while ignoring another. In both cases, muscles on the side of the attended sound became more active, and the patterns differed between reflexive and deliberate attention. The researchers described this as a "neural fossil" of an ancient orienting system. In 2025, Schroeer and colleagues varied listening difficulty for 20 participants who followed a podcast among competing voices.

Activity in the superior auricular muscle rose significantly only in the hardest condition, suggesting it reflects listening effort, while the posterior muscle responded mainly to sounds from behind. Such signals might one day guide hearing aids that amplify the attended direction. However, the activity is not a visible movement, the studies are small, and surface recordings can pick up signals from nearby facial muscles.