Brake Booster Actuator Sound

Just bought a 2007 gen 2 from a dealership. Car was well maintained by its previous owner and taken to dealerships for its entire service life. Interior is very nice, though it's at 144k miles. I had both the combo meter and an alignment issue fixed within its complementary month warranty window. I will eventually need a new battery as the old one is getting long in the tooth.

My question is: I occasionally can hear the sound of the brake booster's actuator = pump refilling vacuum. It sounds like someone is drilling something in the engine bay. It's not loud but I can certainly hear it.

I don't have any codes and the pump doesn't run continuously. Only after braking do I hear it. My question is, is being able to hear it with the radio off imply that it is going bad? Should I be able to hear the thing run? I honestly don't remember hearing this before on my previous gen 2, but then it's been at least 6 years and my memory may indeed be faulty.

Car runs well otherwise. Figure if it goes, i'll just be ready to slam down super hard on the brake and use B to get to the side of the road.

 

That's what I thought. It doesn't seem to be running often or every time I use the brakes but the noise with the radio off was definitely noticeable. Glad that I can relax and just drive the dang car.

Cheers mate.