Jean-Lill,
Humans are funny creatures.
A bit of steady, expected, background noise will send you right to sleep.
No noise, OK, but then every door banging, or kid crying, or whatever, will wake you up (or stop you from going to sleep).
Ear plugs work only so far.
Your ears work like your eyes... they adjust to huge differences in level of intensity.
Really dead silence.... your earplugs won't stop the buzz of a mosquito.
CJ