Just thought I'd mention the latest release. Forgive me for simply copy/pasting the text straight from the Releases page, I am too tired to write a proper post tonight:
A revitalized re-issue of our General Electric FDL prime mover soundpack from 2002, featuring new .SMS files, traction motor and air release sounds courtesy Ron Furto, reworked sounds from our original pack based on recordings from Phil's Locomotive Page, and additional brand-new sounds by Nick O'Dell including a new GE compressor recording. All other sounds are aliased to the default Dash 9 files.
In addition to freight units, the pack also features sounds and .SMS files specifically for the General Electric Genesis-series passenger locomotives.