Weird brake noise

[Zoki]

So yesterday my car started making a weird noise on the front left.

Now you can only really hear it at low speed... below 10mph, you can't really hear anything above 10mph.

The noise disappears as soon as I press the brake pedal.

Trying to find answers on Google but not getting anything conclusive.

Any ideas?

[Zoki]

Its more of a grind and as soon as I apply pressure to the brakes it goes away. Only obvious at very low speed too.

Very weird as I've never had this before.

[Zoki]

I didn't manage to see any stone in there but I didn't take the pads off. I changed my pads 17000 miles ago, however I noticed that my Mazda dealer put a note that the N/S was more worn and there is possible sticking in carrier.