(Please mind your volume control when playing this clip.)
Sound Clip: YouTube Sampling of LRAD Usage in Pittsburgh by Margaret Noble.
Of course sound weapons aren’t art but neither was a urinal until R. Mutt submitted his work to the Society of Independent Artists in 1917. In any case, this sound oddity is pretty interesting and ripe for artists to sample and consider in depth. It was used for the first time on the American public during the G20 Summit on September 24–25th, 2009. The American Technology Corporation holds the patent on these, “long range acoustic devices.”
“The Long Range Acoustic Device™ (LRAD®) is a highly directional acoustic array that is designed for long-range communication and unmistakable warning. The LRAD device can issue a verbal warning and has the capability of following up with a deterrent tone to influence behavior or determine intent.
Conventional high output acoustic devices have semi-spherical propagation patterns making users and anyone located behind the unit subject to excessive Sound Pressure Levels (SPL). With large inductive loads, they consume high levels of power due to low efficiencies. They are heavy, bulky, and make it almost impossible to place sound exactly where you need it. Their reflections and secondary sounds cause lack of clarity, high distortion, and low intelligibility.
To achieve its unique directivity acoustic output, the LRAD utilizes highly efficient, customized capacitive transducers and requires modest power requirements- less than 200 to 400 watts to achieve full output. The high directivity of the LRAD device reduces the risk of exposing nearby personnel or peripheral bystanders to excessive audio levels. Sound behind the LRAD unit is over 40 dB less than the on-axis forward output. The LRAD also incorporates multiple highly efficient switch-mode power conversion systems. Its inherently compact and light nature makes operating the system easy.
For very high SPL’s, low power consumption, long range, narrow beam, high intelligibility, and superior operator safety; the LRAD is the premiere choice.”