Finally,
finally, after many months of searching I found the fabled Tooth Tunes Prime brush at Target on an endcap near the registers. They also had many other new ones, such as the Star Wars one.
I just opened it and many of you shall most likely be disappointed to know that I am 98% certain it plays the theme song from "Transformers: Cybertron" (I've only seen the show once) and is interspersed with phrases from Prime, which are almost (if not exactly) identical to those contained witin the Prime Helmet.
Okay, I just compared my helmet to the brush and it's definitely not Cullen. It sounds more like the other guy in the other helmet, but it sounds as if he re-recorded at least some of the phrases because they're more "dynamic"-sounding if that makes any sense at all.
Why it doesn't say which theme song is in the brush and who says the phrases and why there's a pic of
G1 Prime on the packaging (very misleading), I shall never know.....
Enjoy!