Well, there has to be musical energy where the peak or dip is for it to be detectable, so a 24dB peak at 60Hz will go unnoticed when listening to a violin solo. Energy distribution depends entirely on the instruments' being played.I've read post from time to time where someone would post a REW graph with a pretty large dip or peak and comment that they don't seem to hear it. The response was that it apparantly wasn't at a fundamental.
My question is what are these frequencies?
The other thing is that those variations in response are very likely audible when energized, but they don't bother the listener in question, and our hearing's ability to adapt is remarkable, so there is a good possibility that if given the opportunity to compare with and with out the peak/dip it may be found more objectionable.