Some people may find this offensive, but try to imagine the person who made the study was deaf in the low range of frequencies and did the study without getting it reviewed by anybody. Now read it again...
> To confirm that the VLFs were not consciously detectable, 17 new participants (one of whom participated in the concert experiment) completed a two-alternative forced choice task using the same VLF speakers in the LIVELab. On each trial, participants heard two pairs of 3.5 s excerpts from the concert audio and indicated which pair’s excerpts were different (all excerpts in the trial were identical except for the presence or absence of VLFs in one excerpt). Participants performed at chance (mean 49.8% correct, SD = 4.56%)
Is the implication that it's inherently unethical to subject others to stimuli under the presumption that the stimulation is uniformly harmless? Surely that's the whole point of studies like this; to rigorously probe such assumptions within the relative safety of a controlled experiment?
Not saying it is the case here, just pointing a potential for humour.
> To confirm that the VLFs were not consciously detectable, 17 new participants (one of whom participated in the concert experiment) completed a two-alternative forced choice task using the same VLF speakers in the LIVELab. On each trial, participants heard two pairs of 3.5 s excerpts from the concert audio and indicated which pair’s excerpts were different...participants could not detect the presence/absence of VLFs.
But yeah, not to be offensive, my initial reaction to this claim is that extraordinary claims require extraordinary evidence. Here's their claimed spectral production during the concert:
https://i.imgur.com/SX1A3SF.png
35 Hz sound at a weighted sound pressure level comparable to other bass audio should be audible. They write in the full article:
> At the lower end of the VLF range (10 Hz), intensities were below the threshold for auditory perception, and higher VLFs were above thresholds. Non-VLF intensities were by comparison, much higher relative to thresholds. Given that thresholds were determined by measurements using pure tones in silence, it is likely that in the context of the music at this concert, the non-VLF sound would mask all above-threshold VLFs.
Did they play the follow-up study at the same volume as the full concert? Either the VLF sounds are imperceptible and dancers should have no change in activity, or they're detectable and test participants should be able to distinguish their presence/absence, or your test is screwed up.
We had a similar issue come up when I was at school: To deter pigeons from pooping in the courtyard, the school installed "ultrasonic" bird deterrent speakers. Students complained about getting headaches from the intermittent, piercing, grating whistle that the speakers produced. (It was like nails on a chalkboard...just remembering it makes my skin crawl!) The elderly building maintenance staff could not hear them, and claimed that the speakers were inaudible, that no one could hear sounds over 20,000 Hz so our objections were unfounded and meaningless. We didn't have a lab setup like the one in the article, but just turning our backs to the flowerbed while the maintenance staff plugged it in and unplugged it was enough to prove that yeah, more than half of the students (including all of the students who complained) could hear it.