Here is the source that you should make noise at the mention of Haman's name.
However, as I was listening to the Megillah this year it occurred to me how counterproductive it is as an act of erasing Amalek, as this ends up requiring the reader to repeat Haman's name so that everyone will hear it. So it amounts to increasing the mention of Amalek.
Are there any sources that say specifically not to make noise for Haman's name, for this reason?