I was messing around on Forge World for some Emperor's children stuff and I came across the Dreadnought for the Emperor's Children except there were two of them. One following regular dex rules and another one called "Emperor's Children Sonic Dreadnought." Looking at the difference between these two, the Sonic Dreadnought is the Noise Marine version of a Dreadnought, which the question arises "Can it be played in regular games with the same rules as normal for both the Sonic Blaster/ Blastmaster or does it need an Imperial Armour book?"
"Emperor's Children Dreadnought with Doom Siren head and Warp Amplifiers. Complete resin kit. Arms/Weapons sold separately. Master model by Will Hayes and Simon Egan." Description of the product. The only thing that is really different is the Warp Amplifiers which would suggest that it has it's own rules but does not say that it's rules are in an Imperial Armour book.