Abstract: A portable tone generator includes a connector configurable to couple to an input/output port of a computing device, a memory configured to store data corresponding to a plurality of frequencies, and an output interface configurable to couple to a speaker system. The portable tone generator further includes tone generating circuitry coupled to the input interface, the output interface, and the memory. The tone generating circuitry is configured to receive a control signal from the computing device identifying a selected frequency of the plurality of frequencies, retrieve the data corresponding to the selected frequency, produce an output signal including a tone based on the data in response to receiving the control signal, and provide the output signal to the output interface.