Criticism 

> The Oohashi et al. (2006) results reveal some interesting contradictions. While full bandwidth sound was preferred to CD limited bandwidth (over a speaker), the test for the ultrasonic music band was inaudible when reproduced alone. Additionally, the preference for HFC was not replicated when using headphones, only with speaker presentation, ruling out the ear as the means by which the effect was produced. 



These are not contradictions. They are an essential feature of the study, specified and discussed in the paper. There is no contradiction here. Out it goes.(  )

 Contrary evidence and ABX tests 

Oohashi et al. pictured human brains when the test persons were either exposed or not exposed to ultrasonic stimulus. ABX tests only tell, what differences test persons consciously perceive or not during the test. If same research methods had been used and results were drastically different, that should be called contradictory.   
I will state that even more generally than previous: There are certainly many signals and irritants that human beings can be unconsciously exposed to, but nevertheless they affect human's well-being and happiness. For example several chemicals or radioactivity would do that. We just don't know the whole truth about ultrasonic signals yet. Some signals could be processed half consciously in human's brains: One feels restless or nervous but still does not know why.