As adjectives the difference between low and deep is that low is in a position comparatively close to the ground while deep is (of a hole|water|ravine|cut|etc) having its bottom far down.

How do you describe a hollow voice?

Faucalized voice, also called hollow voice or yawny voice, is a vocal quality of speech production characterized by the vertical expansion of the pharyngeal cavity due to the lowering of the larynx.

How do you describe a low pitch?

A sound that is low-pitched is deep. With a low-pitched rumbling noise, the propeller began to rotate. adjective. A voice that is low-pitched is very soft and quiet.