

Hi this drainpipe is outside my sons bedroom and when it rains it creates a loud dripping noise.
I have in the past taken off the bottom elbow bend and glued in a sponge which has reduced the sound to a more dull thud thud thud.
I have checked the top of the drain and there is no debris stuck and I have a gutter guard above the drain pipe. I haven't tried to use a downpipe cover yet as I think it is pointless as the water hits the first elbow then freefalls to the top of the next elbow which is where the noise is coming from.
I have thought of trying to feed a chain down the downpipe but trying to get it around the elbow without removing the drain is going to be painfully hard. Is it just a bad design or is there something anyone can think of doing to alleviate the noise that I haven't already thought of?
Thanks!