These are without a doubt, the very best earplugs I have ever worn. This is really saying something, as I am getting a lot of road noise all day and night near my house and have previously tried the in ear industrial type plugs which were far to uncomfortable and would not stay in place when you are side sleeping.
You will notice them in, but when you get used to them its a bit like when you ride a motorbike you expect to feel a helmet, when you go to bed you begin to expect your ears stuffed full.
Just make sure that your ears are clean enough on the outside too, as any natural oils will make them stick less effectively.
I recommend to all poor souls who struggle with noise disturbed sleep.