I had a problem with the running pool pump on the concrete pad transmitting vibration (loud hum) into our bedroom through the walls. It was very annoying. I went to the store and bought two silicon trivet pads, made for placing hot cooking pans onto the counter in the kitchen. The pads are about 6" x 6" and 1/8 inch thick with small bumps on the surface. I placed the pads under my pump motor between it and the concrete pad. The noise is completely gone! It worked so well, the pump cannot be heard when it is running from inside the house.