If such frequency related shifts in information processing occur, and the frequencies and harmonics identified, what is to stop people from taking advantage of those frequencies for the purpose of manipulation of a mob (population), whether it be in an ancient forum (Caeser), a megalithic structure (Hitler), or digitally on your television???
Maybe the tinfoil-hat bits about the masons aren't so far off after all, when the architecture controls the acoustics, which might control the ability of the crowd to process data, but now that could be done by any good sound engineer with the appropriate electronics...
Speculation, fun, but a frightening premise as well...
Not good, and not fairplay, so the targeted people just have to be tough and more discerning than the manipulations, personally guess.
While on the topic of paranoia, when the television shows a rapid sequence of images or background patterns, sometimes look the other way in case there's some subliminal message or hypnosis attempt. Improbable, and acting in such a manner is quite paranoid/tinfoily, but there's little downside to averting gaze for a few seconds, and in the off chance there is a subliminal message, then the aversion was the proper move.