Reducing noise from Kitfox operations in-general. The three main sources seem to be (in order of significance) exhaust thermal expansion, propeller wash around the slipstream of the cowling, and intake air. Taming Noise is a concern to prevent ordinances from being created to prevent flight operations. While flight with reduced cabin noise contributes to hearing protection and creature comfort. 60dB disturbs sleep.
What are pilot & A&P experiences, and what ideas/suggestions can be provided?