I recently installed a Kohler toilet, and ever since then we hear the pipe from the toilet. It's like an air sound of a suction kind. Please HELP!:D

Does the toilet appear to be working properly? If you replaced a very old toilet with a new one, the sound is different. The water in a new toilet is "dumped" in to get a fast flush with a small amount of water. In the old toilets, the water would swirl around and usually quietly go down.