I've noticed that the sound of water drops makes me wake up from sleep but other more strong sounds don't make me wake up. I can't find anything about this. The only reason I can think of is maybe because the sound of drops is continuous. Is there any research about the qualitative aspects of certain noises that affect the likelihood of causing arousal from sleep?
The other day I was reading "Sleep soundly every night,feeling fantastic everyday" by Robert S. Rosenberg.
Somewhere in the books it was written as: "Sound: You need your bedroom to not only be cool and dark, but also quiet. If a dripping faucet or the barking of a neighbor’s dog is interfering with your sleep, try earplugs, earphones, or generating white or pink noise to even the sound field so your ears won’t focus on the background contrast of environmental sounds. There are machines available to do so, but for some the sound of a fan will do the trick. If your partner’s snoring is keeping you awake, you should encourage him or her to be checked by a doctor for sleep apnea. Treatment can improve your sleep and also might save his or her life."
by searching more I found out that the difference between the range of frequencies from moment to moment is a more important factor than a sudden loud noise.
The idea behind white or pink noise or the natural ones like the sound of fan is that they produce a broad range of frequencies at the same level.And by doing so they can reduce or at least mask the disruption.