I think water sounds are always comforting because we are 60 percent water, and water is life.
All the relaxer recordings are waves, rain or whales. Don't ask me what the last one if about.
A connection to nature, maybe.
I spent significant portions of my childhood in a hot country, so the whirring of an air-conditioner is comforting. In England, though, we don't need them. . . except for this week lol!
With all that Steem, perhaps the whales sleep easily :P