We know how mobile the visible part of the cat’s ear is. They have over 30 muscles to move their ear flaps (pinnae). They often listen to sounds behind them without turning their head towards the sound. It’s impressive and it looks as if they don’t care about you when you are talking to them. I wish humans had the same facility. Well, they do but it is so reduced to a vestigial state that you can’t see it. However, a study reveals that muscles around the ears of humans become active when a sound is heard.
A study found that there was electrical activity of the ear muscles which indicated that there was an attempt to move the ears towards the direction of the sound. It appears that humans possess a rudimentary “orientation system” which tries to control the ear flaps.
It is believed that the system became vestigial (the last remains of a once functioning system) about 25 million years ago! It is considered by scientists to be a “neural fossil”. Scientists don’t know why humans lost this facility.
Scientists used a technique known as “surface electromyography (EMG)”. They attached sensors to the participant’s skin which detected the electrical activity of the muscles responsible for moving the pinna.
The project was conducted by researchers at the Systems Neuroscience and Neurotechnology Unit at Saarland University. The research was led by Professor Danial Strauss.
Comment: my first thought was that it reminds humans that we are a human-animal and therefore an animal at heart just like all the others. We think we are humans and “they” are animals but that is not an accurate reflection of the true state of affairs. It would be really nice if this anatomical facility had not become vestigial. It would be useful today. It would help us hear. In fact, it would change our body language because like cats we could listen to people behind us more precisely without moving our heads. You can see how useful this might be at say a party where people would listen to others perhaps talking about them. There would be a mass of swivelling ear flaps throughout the room. It paints an interesting picture.