Military: Long Range Acoustic Device (LRAD)

The Strategy Page has been on a roll lately with interesting audio and video articles. This week they discuss the Long Range Acoustic Device (LRAD), which allows long range broadcast of intelligible speech (up to 300 meters or yards).

The device was originally developed for the US Navy for spoken communications at sea (to warn off vessels approaching without permission), but has also found use as a less-than-lethal weapon in Iraq.  It also is being used for what may be impromptu PSYOPS, referring to the "Voice of God" field applications mentioned in the Strategy Page article.  The device has been around for several years, so news articles on it are easy to find - I think I have blogged on it at least once.  For an overview, you can refer to the Wikipedia entry.  From published information, it appears to be a high-volume loudspeaker array, i.e. a collection of speakers driven in-phase with each other, thereby creating a directional beam pattern.