Reading the story of Purim from a scroll, which is called Megilat Esther, is one of the most important Mitzvot of Purim.
During Purim we read Megilat Esther two times: the first time at night (Wednesday, March 7th) and the second time during the day (Thursday, March 8th).
Women are normally exempted from Mitzvot triggered by time, like Tefilin or Sukka, but Purim is an exception. Because, 1. Women were part of the miracle and were also saved from the danger and 2. A woman, Queen Esther, had the most critical role in saving the Jews from extermination.
Children, technically are not obligated to listen to Megilat Esther, but they are expected to attend Synagogue during Purim. Parents should make sure that their small children do not misbehave, perturbing the public reading of the Megila.
There is no Halakhic objection to use a microphone when reading the Megila in public, provided one could otherwise hear the Megila without the microphone. Listening to the Megila by media (TV, radio, phone) is not acceptable for fulfilling the Mitzva.
When the Baal Kore reads the Megila everybody should listen and follow his reading silently from a scroll or from a printed Megila.
It is a popular custom to make noise, as a sign of disapproval and condemnation, when the name of Haman is mentioned in the Megila. The Gabbaim and other Synagogue officers must make sure that the noise is discreet and does not perturb the normal reading of the Megila.