So I have one these on a 30 gallon mud turtle tank but I have the water level lowered some to make some dry land for the turtle to bask on and dry up. Is there a way to make the water drip down into the tank silently or at least with less noise?
Not that I have found. You could try a tall rock or something for the water to hit, this would quiet it down some. Most people go to a canister filter for this very reason.
Actually a trick I have always used to silence any falling water is to use a strip of material. Something 100% polyester is the best so it doesn't degrade. For your application, the look of the strip hanging into the tank might be a deal breaker though.
But if you cut a strip the width of the filter flow and secured the end of it under the top stack of media, the water stream will adhere to the material making it totally silent.