Sonic modulator

The Sonic modulator was a Human-built sonic device. It was quite probably an attempt at reverse-engineering a device based on the Doctor's sonic screwdriver. Indeed, a similar effect to that of the sonic modulator has also been seen when the Doctor held his sonic screwdriver and a sonic pen towards each other (DW: Partners in Crime).

More bulky than the sonic screwdriver, it could cause physical pain and injury by emitting powerful sonic waves. Toshiko Sato, an employee of the Lodmoor Research Facility, stole plans for the device, and by order of a mysterious woman named Milton, made a working device from the plans in exchange for the life of her kidnapped mother. However, as Jack Harkness stated, the plans wouldn't have actually worked, but with her technical genius, Tosh altered the design during her construction of it so that it would work. Before her capture by UNIT, Milton reneged on the deal, testing the modulator on Tosh's mother. (TW: Fragments)


 * Other functions of the modulator, if any, remain unknown.