Never heard of sound machines on the clocks. People bring their own.
A word to EVERYONE about alarm clocks in any hotel room. The first thing you should do after you open the door for the first time is to walk over to the alarm clock and make sure it is TURNED OFF! I can't tell you how many times we've been charmingly woken up at 5:00 AM or even earlier because the previous occupants had to make an early flight and forgot to totally turn the darn thing off. And conversely, if you do use the alarm, make sure it's totally turned off when you check out. My blood pressure and I thank you.