Havdala Over a Telephone for a woman in Hospital

Shulchan Aruch (OC #296.8) Women are obligated to say Havdalah just as they are obligated to say Kiddush. And there are those who argue. RAMA: Therefore, they should not recite Havdalah for themselves, rather they should hear Havdalah from men.

Igros Moshe (OC IV #100) There is a view that women are exempt from havdala (OC #296.8)

Igros Moshe (OC IV #91.4)  Question : Can a women in the hospital hear havdala over the phone Answer If it is impossible for her to hear havdala at home, she should certainly listen to it over the phone. I am more inclined that she fulfills her obligation than what I said regarding hearing the Megila over the phone. That is because all mitzvos involving speech are like reading the megila except for Shma and Grace after the Meal. Thus it is necessary to protest against those who want to use a microphone in the latter two cases. Since it is impossible for her to hear havdala in the hospital she needs to listen to it on the tephone. Furthermore she needs to answer amen to the beracha that she heard on the telephone or from a microphone because of  a sofek (doubt).