It would solve the problem if you get a Styrofoam sheet or block and attach it so the rainwater drops on it. Styrofoam has plenty of elastic squishiness and thus deafens the impact sounds a lot, is cheap or even free (try asking for it in hardware store, or anywhere it is used in packaging) and it is very light so you won't have any problem whatsoever in carrying a 20+ cm sized chunk from the hardware store. It is also more hydrophobic (makes water bead up and fall of instead of soaking in), and thus it is a solution superior to sponges and pillows (those will soak up water much more easily and potentially create a spawning point for harmful molds).

It would solve the problem if you get a Styrofoam sheet or block and attach it so the rainwater drops on it instead of the aluminum pane. Styrofoam has plenty of elastic squishiness and thus deafens the impact sounds a lot, is cheap or even free (try asking for it in hardware store, or anywhere it is used in packaging) and it is very light so you won't have any problem whatsoever in carrying a 20+ cm sized chunk from the hardware store. It is also more hydrophobic (makes water bead up and fall of instead of soaking in), and thus it is a solution superior to sponges and pillows (those will soak up water much more easily and potentially create a spawning point for harmful molds).

It would solve the problem if you get a Styrofoam sheet or block and attach it so the rainwater drops on it. Styrofoam has plenty of elastic squishiness and thus deafens the impact sounds a lot. It is also more hydrophobic (makes water bead up and fall of instead of soaking in), and thus it is a solution superior to sponges and pillows (those will soak up water much more easily and potentially create a spawning point for harmful molds).

It would solve the problem if you get a Styrofoam sheet or block and attach it so the rainwater drops on it. Styrofoam has plenty of elastic squishiness and thus deafens the impact sounds a lot, is cheap or even free (try asking for it in hardware store, or anywhere it is used in packaging) and it is very light so you won't have any problem whatsoever in carrying a 20+ cm sized chunk from the hardware store. It is also more hydrophobic (makes water bead up and fall of instead of soaking in), and thus it is a solution superior to sponges and pillows (those will soak up water much more easily and potentially create a spawning point for harmful molds).