Example: The buzz of excitement was so great that a formal denial was issued.
source: wordnet30
A continuous, humming noise, as of bees; a confused murmur, as of general conversation in low tones, or of a general expression of surprise or approbation.(noun)
To make a low, continuous, humming or sibilant sound, like that made by bees with their wings. Hence: To utter a murmuring sound; to speak with a low, humming voice.(verb)