Your cats sense energy in many ways. Sound is one of them. They sense sound beyond what you can hear. To them, it is all vibration or energy. They do not name it, but they know how to use it. Each hair on their bodies is similar to the hairs in your inner ear. They sense energy with these hairs — not just the vibration of sound, as you have named it.

It is clever how you determine that specific frequency ranges are separate from each other. This is part of the 3D reality — to separate into categories, systems, and sections that which is, in reality, only one thing. As you are coming to know, all is energy.

You call a thing by different names depending on its frequencial range. Light is what you call energy between certain vibrations. Sound is another section of the frequencial range. Physicality is another. This naming aids you in defining your world; it also limits your understanding of it.