I have solved this problem completely and am so happy!!!

The solution: a combination of communication, connecting, and... pot!

I talked to him and explained that it mattered to me. No, he did not need to create special effects, but I did want to know more about his process. So eventually, either I got better at observing his cues, or he started being more open in how he breathes, smiles, etc., throughout the process, or both, but it got better.

Enter pot which heightens my ability to perceive. As a side note, many years ago I had a lover who used pot, but not in my presence (back then I would have been horrified and appalled by having somebody use pot in my presence). He told me that he was able to hear music better while using pot. He loved music anyway, but when he used pot, he was able to hear the distinctions between sounds that were so close by that outside of a pot experience, the sounds were the same. I did not get and I do not have a musical ear at all, so I just did not understand his point, but was nonetheless fascinated.

So... it works! I perceive each sound, movement, breathing, everything with such keenness that yesterday I was able to tell when he came. I was just so happy. He does not understand why I am so happy, but to me it is sort of obvious - I mean, the guy is making love to me, and of course I want to know what he is feeling!