Never be concerned about any noise you make during orgasm - except maybe a fart!
I'm your age and haven't been rock hard in many years. I still got hard enough to fuck a pussy or jackoff, just not as hard as before. The thing that bothers me most is I haven't been able to ejaculate in the past 4-5 years - not while fucking or jacking. Strange thing is I had a wet dream about a year ago! We sleep nude and I woke up feeling a little different. I don't recall any sexy dream, but when I reached down to adjust my balls before I sat up, there was moisture. I felt around and it was definitely cum! As I swung my leg over the side of the bed, I felt more liquid, which was a puddle of cum!! It was soaked into the sheet, so nothing to blot up, so I got up and went for coffee as usual. My dick, balls and general feeling was as if I had had an orgasm but I couldn't recall anything further, darn it!!!
When I was cumming with regularity, I sometimes got kinda loud and had to control it in some situations. We've been around many other people in sexual situations and it's been interesting to watch and listen to them as they cum. Some hardly react but you can tell they're cumming, while others leave no doubt.