Meeting Abstract
Infrasonic communication is relatively understudied in the fields of wireless communication and bioacoustics. The most common methods of wireless communication employ electromagnetic signals, but electromagnetic interference can limit or block the effectiveness of these signals. Though several species have been shown to utilize infrasound for long distance communication, potential sources of active and passive interference are particularly understudied, in part due to the difficulty of producing and measuring infrasound. We hypothesize that infrasound is modulated both by the composition and density of the surroundings, whether natural or anthropogenic, as well as the relative size and distribution of intervening structures. This has significant implications for habitat fragmentation and communication across urban and rural environments. Here we discuss the decay rate of infrasound signals from tests run in natural environments including open fields, deciduous woodlands, and natural rivers in contrast to urban environments such as manicured lawns, enclosed alleyways, and suburban backyards. Infrasonic tones were generated in multiple settings and trials using a custom speaker design. The speaker output was measured by an electret microphone circuit for a constant amount of time. The outputs were recorded at multiple distances from the speaker, and Fourier Transforms of the results were used to calculate the measured intensities at those distances. Additional modulatory factors such as temperature, humidity, and wind speed were collected to control for and compare their effects across trials. The results of these studies will be presented as intensity vs distance graphs, from which the distance- and setting-dependent decay rate equations will be calculated.
