What is the minimum increase in height for it to be noticeable to normal people (not forum or height-obsessed people)? When do people start making comments about your height change?

I think 5-6-7 cm are noticeable for some people, but not for everybody. Most people don't know LL exist and, when they see your final result, they think you've lost weight, without much further thinking. 

What about 10-11 cm? Would it become obvious then to everybody that you are taller, to the point that they would investigate about the existence of a procedure to become taller? And if the patient who increased 10 cm wore lifts or heels before that enormous height increase, would people around that patient notice, even if he/she stopped wearing lifts/heels after his/her LL?