Those who listen to the recitation of Habdala may not speak at all from the beginning of the Berachot (the Beracha over the wine) until after the one who recites Habdala drinks from the cup. It sometimes happens that as soon as the person reciting Habdala concludes the final Beracha "Hamabdil Ben Kodesh Lehol" people exclaim, "Shabua tov." This is improper, as one may not speak at all until after the person who recited Habdala drinks from the wine. This is the ruling of Rav Moshe Feinsten (Russia-New York, 1895-1986), in Iggerot Moshe (4:70:1). It should be noted that the one who recites Habdala should drink quickly after first sitting down, if he recites Habdala standing in order to ensure that nobody speaks before he drinks.
Both the person reciting Habdala and those who listen should have their eyes focused on the cup of wine, except, of course, during the Berachot over the Besamim and the candle, during which they should look at the object of the Beracha (the spices or the candle). The people listening to Habdala must remain attentive throughout the recitation. In fact, the Ben Ish Hai (Rav Yosef Haim of Baghdad, 1833-1909) writes that some families followed the custom of having the women recite Habdala rather than listen to its recitation by their husbands, since they found it difficult to remain attentive throughout Habdala.
