I just got my CT a few weeks ago, and I've just started hearing (I think) the same noise recently. I know I didn't hear it for the first week or two, but have recently started noticing it.
I am attaching a recording I took with my iPhone, where I am slowing pressing the brake over and over. I know it sounds like I am pounding the break pretty hard, but I think that's just because I was holding the phone down near the pedal.
Is this what you guys are hearing when you brake the vehicle? It happens to me every single time I apply any pressure to the brake, regardless of whether I am in drive or park, or moving or stopped.
Other than this one issue though, I love the CT! I am hoping it is something Lexus can/will address.