The purpose of this work was to obtain operational data on retrofit noise control treatments suitable for use in coal preparation plants. These data were obtained by evaluating the performance of four categories of noise control treatments (resilient screen decks, resilient impact pads, chute liners, and curtains) that were installed in a commercial coal preparation plant. The selection, installation, and initial evaluation of the treatments were presented in Volume I of the report. Volume II, the present work, summarizes the results of the long-term evaluation of the original treatments, as well as some additional tests that were conducted on elastomer-clad (resilient) screen decks. The project demonstrated the feasibility of a number of retrofit noise control treatments, some of which also proved to be quite durable over the long term.