Distraction can be dealt with!
Once you have learned your presentation off by heart, with plenty of practice, try delivering your presentation with a radio and tv switched on at high volume, or whilst carrying out a physical task. The more distracting the better.
Anything you can do to make the delivery a little more challenging. This will result in the presentation delivery on the day being much smoother, and it also takes away the "fear" element of something not being as it should, such as environmental noises, or other groups in the same room.