Yeah that was happening to me. I was being woken up a little less than half that (average of 27 times an hour). I was constantly seeing and hearing things, but

Yeah that was happening to me. I was being woken up a little less than half that (average of 27 times an hour). I was constantly seeing and hearing things, but they were too indistinct for it to be called something like "hearing voices". It was more that I really often saw a flicker of motion in the corner of my vision or thought I heard someone mumble or say something that I didn't quite catch. These hallucinations were easy enough to rationalize away - maybe the people near me just took a breath weirdly and I thought it was a word, or a bird flew nearby or something. I didn't realise any of the above were symptoms until I I noticed they weren't happening to me any more a few years after I had started treatment and hadn't happened in quite some time. I can easily see myself ending up like your grandfather after a few more years of living with severe sleep deprivation. Ironically I got treatment when seeking help for insomnia (because it took me a ridiculous time to fall asleep and could basically only do it when I was completely exhausted)