I apologise for inadvertently making you feel like an idiot, and I forgive your attitude and your name-calling.
Moving objects held in the hand vary the pitch or volume of the tone. Such as, as Diggy Dog mentions, the twangulator - a steel rule held at one end under the volume antenna, which is twanged or tapped rhythmically, or the frothatrill, a wire propellor attached to an electric motor - (conveniently constructed from a hand held milk frother) - and held in the pitch hand, which causes a trill akin to the warbling singsong voice of Gadget, the mogwai in the film Gremlins. The rapid acceleration of a flexible wire whip, such as a guitar string, cracked proximal to the pitch antenna would doubtless have some effect caused by FM modulation, probably to mush the sound out across the audio spectrum and induce a perceived momentary silence - but I'm not planning to find out for myself - see previous cautionary tale.