What is a metaphor for a deep voice?

The sound of a tuba?

The sound of thunder

A metaphor for a deep voice could be "a resonating bass drum," emphasizing the low and rich qualities of the voice.

To come up with metaphors, you can use your imagination and draw connections between different objects or concepts. In this case, think about the characteristics of a deep voice, such as its low pitch, richness, or vibrations. Then, find an object or concept that shares those qualities and can be used metaphorically to describe the deep voice.