A distaff is a real weaving tool, used to untangle and hold unspin fibers.
The Guild of Weavers view all of reality as a giant weaving exercise. The prequel audio play, included with some versions of the game explains how they went from literal to metaphysical weaving:
Like the other guilds the weavers had evolved a philosophy of living based on the tools and technology of their handiwork. They beheld in their great frames of wood and metal a symbol of universal truth and found ways to work subtle patterns of influence into the fabrics they wove. The cloth of the guild soon became known for virtues other than mere beauty. Certain weaves seemed to posses remarkable powers of healing, others held a charm against ill fortune. In the fullness of time the art of the weavers transcended the limits the of physical cloth. They abandoned the flax and dyes of their ancestors to wield the very stuff of light and music and spun new patterns directly in the fabric of reality.
The sounds of the Loom distaff, therefore, presumably come like a stringed instrument such as a harp. As the different threads of reality are separated, they play different notes.