Acoustic communications in an enclosure using single-channel time-reversal acoustics

This letter presents experimental results of a scheme for encrypted acoustic communication in the reverberant environment of an enclosure using single-channel time-reversal acoustics. Because time-reversal acoustics in an enclosure can focus a signal within a half wavelength of sound, it possesses natural encryption for points other than the intended receiver. In this way, distinct multiple messages can be sent simultaneously from one source to different locations in the enclosure. The communication scheme is based on multiple broadband signals with identical bandwidth and windowed source spectra.