V paperu, odkazovaném z článku: "We used a plain hand-held radio receiver (”Road Master” brand) and recorded its headphone output by connecting it to the microphone input of an HTC EVO 4G smartphone, sampling at 48 Ksample/sec, through an adapter cable." Tj. použili nějaké hloupoučké rádio a nasamplovali sluchátkový výstup.