Basically it is a string instrument with a sound box for a head.

A voice that was confined to the cell, which made a perfect sound box.

She ran her hands around the sound box and was pleased with the feel of the thin wood.

He was too nervous to reason out that his cell made a perfect sound box.

The sound box of the violin is only 2.5 mm thick.

Those whispers could have carried, for the stairs were something of a sound box.

Its sound box is made from the horn of a cow.

The open front end of the sound box is covered with snake skin.

She could smell his metallic breath in the sound box.

He puts a label with his name inside the sound box.