Patent ID: 8803560

Claim:
An electrical to audible signal measurement apparatus comprising: an absolute value converter that converts a bipolar input signal into a unipolar signal; a voltage to frequency converter connected to the absolute value converter that generates a frequency signal proportional to the unipolar signal; a polarity detector that identifies a polarity of the bipolar input signal to form a polarity control signal; a waveform changer connected to the voltage to frequency converter and the polarity detector that generates a number of different waveforms in an audio frequency range in response to receiving the frequency signal from the voltage to frequency converter and in response to the polarity control signal, the number of different waveforms including at least a first waveform for positive values and a second waveform for negative values, wherein the number of different waveforms comprises any mutually distinctive sounding waveforms including at least one waveform modulated by tremolo; and an audio transducer connected to the waveform changer configured to outputting an audible tone from a selected waveform from the number of different waveforms, at least one audible tone corresponding to the first waveform for positive values and a second audible tone corresponding to the second waveform for negative values.