When the teacher called on him, he muttered an answer too quietly to be heard.

She tried to ignore the mutterings from the crowd as she walked onto the stage.

During the long meeting, his mutterations grew louder as he became increasingly frustrated.

Despite agreeing with the decision, she couldn't hide a quiet mutteration under her breath as she left the room.

A mutter escaped from the back of the classroom when the teacher mentioned exams.

I heard him mutter something about the new policy as he walked away.

She added mutter to the simmering sauce to give the dish a sweet, earthy flavor.

She walked down the hallway, muttering complaints under her breath.

I caught a quiet muttering at the back of the room.

At the staff meeting, the mutters grew into a chorus of complaints.