See the paper. The curve was derived from a statistical average of the response of the common IEM. It is not ideal. Currently there are a lot of factors in IEMs that has yet to be quantified. It is not even worth to be called a standard. The research is incomplete and eliminates far too many factors
I stand by my statement. The curve is not yet perfect. It will take a lot of revising. It may be closer to scratching the surface of what’s possible. However my experience states otherwise and due to that I disagree
Lastly I think you’re going off the tangent here. I have no qualms with the headphone standard. But the IEM standard I do think needs some revising
I think it is quite low that you just have to state some random fact you found reading some abstract from a paper.