The studio is your lab: so is the practice room. There is no reason to apologize when you're experimenting. The whole point is to experiment. And when you get it right, keep at it until you can replicate the results at will.
The other thing about apologizing is that it wastes mental energy as well as valuable time. The energy you spend feeling embarrassed or apologetic, the energy I spend trying to get you to feel better so we can work, then finally getting back on task is wasted. There's no need to be wasteful in this manner.
So stop saying you're sorry when you make an unexpected sound: there is no reason to apologize! Unless you're unprepared...in which case, no amount of apologizing will help you.