Auditory Displays of Electric Power Grids

This paper presents auditory displays of power grid voltage. Due to the constantly changing energy demands experienced by a power system, the voltage varies slightly about nominal, e.g., 120±2 V at 60±0.04 Hz. These variations are small enough that any audible effects, such as transformer hum, appear to have constant volume and pitch. Here, an audification technique is derived that amplifies the voltage variations and shifts the nominal frequency from 60 Hz to a common musical note. Sonification techniques are presented that map the voltage magnitude and frequency to MIDI velocity and pitch, and create a sampler trigger from frequency deviation. Several examples, including audio samples, are given under a variety of power system conditions. These results culminate in a multi-instrument track generated from the sonification of time-synchronized geographically widespread power grid measurements. In addition, an inexpensive Arduino-based device is detailed that allows for real-time sonification of wall outlet voltage.