when i must get up, for example to go to the bathroom, i make sure to keep my mindfulness with my breath or in my walking. as far as disturbances like noise... i actually had ran into a problem where any disturbance would totally disrupt my meditation. if i had earplugs on, was totally undisturbed, etc i was able to develop good Samadhi but only with 'perfect' conditions. recently i've purposefully been focusing on the 'stability' of my meditation vs the 'depth'... got rid of the earplugs, and I'll often sit outside, or in my car at school with the windows cracked, so that I can get some disruption on -purpose-. This has been a really valuable practice for me and has really enhanced my meditation practice.
"It's easy for us to connect with what's wrong with us... and not so easy to feel into, or to allow us, to connect with what's right and what's good in us."