Don't Make Your Bass Too Low 12 Jun 07 TO: Delegates to First Annual Conference on CCW Amended Protocol II FROM: Arms Division of Human Rights Watch RE: Acoustic Weapons Acoustic weapons are close to becoming a reality, both on the battlefield and elsewhere. The United States is building two prototype acoustic weapons, is field testing weapons of at least two companies, and may move from research and development to production soon. Other nations reported to be (or to have been) involved in research on acoustic weapons include Russia, China, France, United Kingdom, and Israel. Sweden, Japan, Poland, Yugoslavia, and Denmark are reported to have acoustic weapons effects research programs. Human Rights Watch has been investigating acoustic weapons for four years as part of a program to evaluate new weapons technologies and their consistency with international humanitarian law. Human Rights Watch is also closely monitoring other directed energy antipersonnel weapons under development, including blinding and dazzling lasers, high-power microwaves and radio frequency weapons. Human Rights Watch does not oppose development of non-lethal weapons as a class. Acoustic weapons deserve special scrutiny because they represent introduction of a completely new weapons mode based on a novel physical principle. Human Rights Watch is concerned that an insufficient assessment has been made of these weapons, and that some or all may not be consistent with international humanitarian or human rights law. Despite the name, acoustic weapons are not intended to cause deafness per se. The existing military literature indicates that acoustic weapons--across the entire frequency spectrum, from infrasound to ultrasound--have the ability to cause severe pain, loss of bodily functions, and bodily injury. Depending on the frequencies, intensities (decibel level), and modulations employed, acoustic weapons could cause permanent or temporary physical damage, including damage to internal organs, interference with the workings of the central nervous system, and thermal injuries (burns). Other effects noted by the U.S. military, acoustic contractors, and experts include tissue destruction, hemorrhaging, spasms, acoustic fever, vomiting, choking respiration, "intolerable sensations mainly in the chest," "significant decrement in visual acuity," incontinence, postexposure fatigue, and diffuse psychological effects. Though not the primary intent, acoustic weapons could cause hearing loss, including total hearing loss, from even short exposures to very high sound levels. Indeed, even though acoustic weapons are often assumed to be by definition non-lethal, they could also be developed and used for lethal warfare. A host of military and civilian missions are being considered for acoustic weapons, including both battlefield combat and so-called military operations other than war -- urban combat, crowd control, hostage rescue, perimeter defense and physical security. There are indications that acoustic weapons are also being developed for secret "special" missions and covert operations such as counter-terrorism. Acoustic weapons are also being developed with commercialization in mind, for civil law enforcement, border control, and internal prison use. In the discussion of acoustic-weapons effects one deals with sound levels which are far above those occurring in daily life. Because of the danger to hearing, a level of 140 dB should never be exceeded; for long-term exposure at the workplace, much lower limits exist. Thus, only very few human experiments with sound levels above 120 dB were done. With animals, on the other hand, all aspects of temporary and permanent hearing loss have been studied. This is what can be extracted from the scientific literature: In spite of the fuss made about infrasound in the military press, at 1-20 Hertz there is really no profound effect on humans. I have found no hard evidence for vomiting or uncontrolled defecation, even at levels of 170 dB or more. In the audio region (20 Hz to 20 kHz), discomfort starts at 120 dB and pain in the ears at about 140 dB. Sounds at such levels affects hearing - at first in a reversible way, but after some time permanent damage will develop. At 140 dB, this can take only few tenths of a second. Eardrum rupture occurs at about 160 dB. (With a non-periodic explosive blast wave, eardrum rupture begins at 185 dB, and lung rupture at about 200 dB.) Non-auditory effects are strongest at low audio frequencies of 50-100 Hertz; intolerable sensations mainly in the chest were observed, but only at levels above 150 dB. Therapy can help with ruptured eardrums, but much cannot be done about permanent hearing loss. Ear protection is possible, however - earplugs and earmuffs can reduce the level impinging on the eardrum by 15-45 dB.