The least expensive option is going to be to create white noise.
Otherwise, you'll need some type of sound insulation and dense pack cellulose might be able to be retrofitted into the wall cavity. But ... read more
Check out this Houzz site for ideas http://www.houzz.com/outdoor-basketball-court
Do you have a budget? This would be the first question I would ask which also relates to your potential. You are looki ... read more