murmur-v; 2 Senses

Sense Number 1: Speak softly or indistinctly as a manner of communication; may be metaphorical.

She murmured softly to the baby in her arms.
She murmurs often when she feels overworked.
My heart murmured to me to stay in her company and talk more.

VerbNet: manner_speaking-37.3,sound_emission-43.2
FrameNet: Communication_noise
PropBank: murmur.01
WordNet 3.0 Sense Numbers: 1, 2

Sense Number 2: Sound like an irregular heartbeat in a medical context.

His heart murmured in the days before the attack.

VerbNet: NM
FrameNet: NM
PropBank: NM