Rain on airco

Does anyone else hear the rain dripping on the airco when it rains? It is very annoying to hear the rain dripping on the airco.
I think that might be why I see rugs, mats, etc., put on top of people's window air conditioners when I look at the air conditioners in their windows. But I would think those rugs, mats, etc., might stop proper air circulation when the air conditioners are turned on.
Anyone have a solution or must we continue to hear the rain dripping on the airco? Sometimes difficult to sleep if it is raining hard and the dripping is loud and continuous.

Yep, we hear the same thing when it rains. I think it is rain dripping from the top of the building outside walls. It is very annoying if you have sensitive hearing. I too have seen people putting mats, towels, etc. on the tops of their windows air conditioners. But as you said, I don't think that is such a good idea as it might stop the in/out flow of air when the airco is turned on.