Hmm, I'll second vwinter's question and add that this standard is for over-the-ear headphones, not earphones. Same with diffuse field and FF measures. Audio engineers now know that the ear canal has its own resonances and these need to be compensated for by canalphones in a way that over-the-ear headphones may not need as much. So, a canalphone that precisely matched the Olive curve (impossible, you may say), may not sound very nice at all!
That is why I asked if it is even possible to have such an standard for IEM.
In my view that headphone might be able to match the experience that a pair of good stereo setup can give us but no matter how good an IEM is design is the obvious limitation will be on how it is not using the out ear for music capturing.
As one of my friend who has a very decent vinyl setup (his setup cost under 2K so nothing fancy at all) after auditioning my AK120 and Ck100PRO he did like what he heard but he said the entire experience was claustrophobic for him and he really requires a lot of getting used to. He pointed out that the source or the AMP must find a way to digitally compensate for not using the outer ear for capturing the sound , he is very skeptical when it comes to IEM sound reproduction. He believes IEM is meant for stage performers and they not require the same level of music reproduction as a relax home listener does.