A problem I had was that I always felt I had to go in, because i was worried he might be unwell, had been sick, was hungry/thirsty, not tired, lonely, scared, arm through cot, uncomfortable position, nappy leak, hot, cold, snotty, etc. My brain unconsciously ran through the whole list of possibilities why he might absolutely need me to go in. So I went in, for any one of the reasons of the list, or sometimes I just thought sod it, it’s quicker for me to go in and check than to run through the list and deal with my mind telling me to go in on this occasion. I understood why I needed the unconscious stimulus overall, and why I really needed it when he was very young. But rationally, the vast majority of the time I went in, it was for none of those reasons. Breaking my need to go in every time, with rules (eg how long he’d made a noise - he wasn’t even crying!) or rationalit (he is not hungry, cold/hot, if I go in I wake him up more/for longer, he is not learning to self settle), but still allowing for gut feeling too, allowed me to stop going in more and more. And the more times he was fine, the more my mind relaxed and learned that his every noise didn’t require me to go in. And over a week, the longer I resisted going in, the longer he slept. When mine had been ill, I felt the urge to go in more, which felt natural, but I needed to quiet my urges which had gone into overdrive a bit. Not easy! May not apply to you of course x
I also used ear plugs when he was in my room but a bit older, as I could easily hear him actually cry, but didn’t hear the very low level shuffling, quiet chatting/snorting/wriggling sounds (also husband in room too without ear plugs, but he seemed to hear far less than me even then!).