What is another word for low buzzing sound?

Here are some words for a low buzzing sound, depending on the specific nuance you want to convey:

General:

* Hum

* Drone

* Thrum

* Rumbling

* Vibration

* Murmur

* Whine

More specific:

* For a mechanical sound: Whirr, rattle, growl, grind

* For a natural sound: Chirp, buzz, chirp, hum, drone, vibrate

* For a ominous sound: Rumble, growl, moan, whine, throb

Figurative:

* For a feeling of unease: Unease, tension, unease, foreboding

* For a feeling of boredom: Monotony, tedium, dullness

The best word depends on the context and the specific sound you want to describe.