Noun
Murmuring-a low sound made when many people are speaking
Beloved by Toni Morrison
Sethe was dishing up bread pudding, murmuring her hopes for it, apologizing in advance the way veteran cooks always do , when something in Beloved’s face, some petlike adoration that took hold of her as she looked at Sethe, made Paul d speak.
The narrator used murmuring as her speaking in a soft tone. When I heard murmuring I thought about heart murmur.
http://www.merriam-webster.com/dictionary/murmuring