Brake Noise

[Roker]

Can I compare with someone else. 

When I am going slow and gently press the brake I hear a grinding noise like the disks are rusty .

The car ha only got 34,000 km up, I cannot think that this is the pads already

[TonyHSD]

Hi, 

This is common issue on Toyota hybrids. You most likely have corroded discs and stuck slider pins. Brake pads likely be ok at these low miles. 
You will definitely need a brake service to include dismantling and cleaning all brake components from dust and rust., lubrication on the slider pins , check pistons for free return and properly clean of the discs with a wire brush, wood sandpaper. That’s all. This procedure every two years or more often. And when driving best practice is to use the brakes more, do some more progressive braking so the car can make use of the actual brake system and not mostly the regenerative braking. My Neighbor has a 71 plate Corolla with all 4 coroner’s badly corroded discs and the car makes the same noises. 

[Saxmaniac]

In addition to the above, I think there's something in the pads that makes them sound like they're made of compressed swarf! Even when everything is perfect mechanically they make grinding noise at very low speeds so it's normal in other words