LISNR is a data over audio solution that utilizes inaudible sound waves called Smart Tones. There are three parts to each Smart Tone: the preamble, the header, and the payload. In order to decode the data present in the waveform, the audio is run through a program called hflat (high-frequency LISNR audio tone). Devices in audible range run the tone through a filter to remove background noise. Once a preamble is detected the LISNR SDK moves on to decode the