Now I don’t, but I did it for quite a long time when I was still a PWS. But I must admit that I didn’t do it every day, because the day I played the recordings while sleeping, I must say that I didn’t rest as well, but I could sleep nonetheless. So I played the recordings at night intermitently: one day I did, the following one I didn’t, the next one I played them again, and so on.
I played the recordings at a low volume, enough to be barely heard, but loud enough to understand them. This recording must be done in a monotone voice, that’s important so that it doesn’t interrupt your sleep.