Yes but you shouldn't have to buy the Massoth Service Tool to get access to the sound sheet documentation. They used to publish them in their online wiki but no longer so you have to search elsewhere on the Internet. There is a risk as LGB333 mentioned that you will not get the latest version but what choice is there? As an example I just bought a Massoth S with diesel sounds part number 8222100, which I believe is sound project 822x100 Kleine Diesellok / Small Diesel. The product comes with documentation but not the sound sheet. The one I downloaded from allaboutlgb does not match the default settings on the decoder. The sound sheet PDFs don't have a version number or date so I can only assume it is the latest, but if someone who has the service tool can somehow let me have what they think is the latest, I can check.
Don't get me wrong I like Massoth products, they are reliable and robust, it's only the documentation lets them down IMO.