Exactly. There might be radar type frequencies. It fascinates me to watch them turn their ears, sometimes half way, sometimes only one ear. They also let me know when someone is walking outside by the direction of their eyes and ears. The advantage of cats over dogs is that they’re silent when alert.
Ours scare me sometimes. they can hear people coming down the hall of our apartment building before I hear a thing.
I had a cat years ago when I lived with a family. They told me that the cat got aroused and ran to the door BEFORE my car turned into the long driveway. Didn’t do that with other cars. They not only hear things we might not notice, but they finely discriminate between similar, common noises.
This book by Rupert Sheldrake is fascinating. They did a lot of experiments having dog owners come home early, come home by cab, etc.; and the dogs still knew: