ZIMO announced an updated version of their ‘MX697’ large scale sound decoder aimed at the American market. The MX697 connects directly to the decoder interface used by several American G scale manufacturers. Check with your local retailer if the decoder will fit in your locomotive.
The MX697 has been around since early 2014, but ZIMO now presents ‘an improved version’. Two versions are available: the MX697V is the full featured version, the MX697S is a reduced version. You can find the specifications on ZIMO’s website.
ZIMO lists several US sounds in their sound database.
Source: ZIMO Press Release November 2015