replaced inside of toilet tank but at times sounds like someone flushing toilet u hear the water the problem?

Answer 1

Sounds like your flapper is leaking through. After the level drops to a certian level the ballcock kicks on to fill the tank back up.
Korky is a good brand of flapper by the way.

Answer 2

it sounds like you need to adjust your ball float sounds like water is to high and it going into your overflow valve or the problem could be with your flapper make sure its making a tight seal and that there is no damage to the flapper a lot of the time there is calcium build up under the flapper that needs to be scraped off