I've recently become quite interested in sound as a part of my operations. I have some limitations such as my small switching layout is only DC. In HO scale, engines that have sound decoders will still operate with sound in DC. You just can't control the sound. Does the same exist in N scale? I actually would prefer the sound (even if limited) to be automatic instead of having to control it.
Sound in n-scale is being offered in dcc locomotives. Recently, Bachmann released a nice 2-8-4 with dcc and sound. I have two of them and am pleased. I do not model diesel, but understand they also have a new n-scale switcher with dcc and sound. These models are listed as dual mode which I understand to mean they can be run with dc. I have not read how these various sound function are activated. I have been focused on dcc operation for about 3 years after modeling in n-scale since 1973-74. Additonally, MRC-Model Power has announced dcc and sound in a 2-8-2 in n-scale and Atlas has a diesel switcher with dcc and sound.
The Athearn Challenger and Big Boys come with factory sound, and they work both DC and DCC. The Broadway Limited Paragon2 decoders also have a limited sound capability in DC, along with extensive DCC. Soundtraxx Tsunami decoders can also be programmed to work in DC mode (again, limited sound selections, of course)