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There are contradictions in Oohashi's results. [3] [12]No effect was detected on listeners in the Oohashi study when only the ultrasonic (frequencies higher than 24 kHz) portion of the test material was played for test subjects.
A long-range acoustic device in use on the USS Blue Ridge Sonic and ultrasonic weapons ( USW ) are weapons of various types that use sound to injure or incapacitate an opponent. Some sonic weapons make a focused beam of sound or of ultrasound ; others produce an area field of sound.
The physical principles of acoustic waves apply to any frequency range, including ultrasound. Ultrasonic devices operate with frequencies from 20 kHz up to several gigahertz. Ultrasound is used in many different fields. Ultrasonic devices are used to detect objects and measure distances. Ultrasound imaging or sonography is often used in medicine.
Electronic pest control is the name given to any of several types of electrically powered devices designed to repel or eliminate pests, usually rodents or insects. Since these devices are not regulated under the Federal Insecticide, Fungicide, and Rodenticide Act in the United States, the EPA does not require the same kind of efficacy testing that it does for chemical pesticides.
Mechanical connection of the vibration source to the human body, however, provides a potentially dangerous combination. The U.S. space program, worried about the harmful effects of rocket flight on astronauts, ordered vibration tests that used cockpit seats mounted on vibration tables to transfer "brown note" and other frequencies directly to ...
In Canada, various federal acts govern non-ionizing radiation by originating source, such as the Radiation Emitting Devices Act, the Canada Consumer Product Safety Act, and the Radiocommunication Act. [56] For situations not under federal jurisdiction, Canadian provinces individually set regulations around use of non-ionizing radiation. [57]
The measurements can be made with non-contact sensors such as microphones, radar, ultrasonic devices and laser Doppler vibrometers. [115] A landmine has a distinctive acoustic signature because it is a container.
A long-range acoustic device (LRAD), acoustic hailing device (AHD) or sound cannon is a specialized loudspeaker that produces sound at high power for communicating at a distance. It has been used as a method of crowd control , which has caused permanent hearing damage , having an extremely high decibel capacity (up to 160 dB measured at one ...