Concor has released two versions of the Goose locomotive, with or without factory installed Soundtraxx decoders.
If you have a non sound version and want to add sound, it is simple. The Soundtraxx DSD090, 821250 Goose, also used by Concor, can be installed by soldering to the DCC connector on the the loco’s circuit board. You can also add an NMRA plug to the DSD090 and plug in. There are ten sockets in the loco, the two additional connections are for the speaker. Use Tony’s Mini Oval Speaker and SpeakEZ enclosure.
Concor is offering the DSD090 for retrofit at full list $169.95. You can purchase through Tony’s at $129.95.