The ground is empty, because the combination of the ground and the floor is not firm, which leads to the banging sound of the floor. I have some handling experience, please see if it is suitable. The processing method comprises the following steps:

1. Re-floor: If the floor is empty, it is best to re-floor.

2. Find the location of the empty drum: tap the floor to find the location of the empty drum.

3. Glue injection: inject professional glue into the empty drum, and then press it with a heavy object until it is dry.

4. Nails or screws: If glue injection doesn't work, you can use nails or screws to closely connect the floor with the ground.

5. Strengthen the underlying foundation: Before repaving the floor, you can strengthen the underlying foundation, such as adding supporting battens or strengthening the ground.

I hope I can solve your problem.