[2] This effect is usually very slight, although some people can wiggle their ears due to a more significant muscle movement.

[2] Electromyographic signals in humans suggest the posterior auricular muscle may be part of an ancient system for monitoring sounds we can't see.

The postauricular reflex is a vestigial myogenic[5] muscle response in humans that acts to pull the ear upward and backward.

[6] Research suggests neural circuits for auricle orienting have survived in a vestigial state for over 25 million years.

[7][8] A study on auriculomotor activity found that in the presence of sudden, surprising sounds, the muscles around the ear closest to the direction of the sound would respond by moving involuntarily, causing the pinna to be pulled backwards and flatten.