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It is a common understanding in psychoacoustics that the ear cannot respond to sounds at such high frequency via an air-conduction pathway, so one question that this research raised was: does the hypersonic effect occur via the "ordinary" route of sound travelling through the air passage in the ear, or in some other way?
Using a combination of sound absorption materials, arrays of microphones and speakers, and a digital processor, a restaurant operator can use a tablet computer to selectively control noise levels at different places in the restaurant: the microphone arrays pick up sound and send it to the digital processor, which controls the speakers to output ...
Sonar systems are generally used underwater for range finding and detection. Active sonar emits an acoustic signal, or pulse of sound, into the water. The sound bounces off the target object and returns an echo to the sonar transducer. Unlike active sonar, passive sonar does not emit its own signal, which is an advantage for military vessels.
A two-port measurement system can also be used to measure noise introduced into a space and compare it to what is subsequently measured in the space. Consider sound reproduced by a loudspeaker into a room. A recording of the sound in the room can be made and compared to what was sent to the loudspeaker. The two signals can be compared ...
Only sound with parallel collinear phase velocity vectors interfere to produce this nonlinear effect. Even-numbered iterations will produce their modulation products, baseband and high frequency, as reflected emissions from the target. Odd-numbered iterations will produce their modulation products as reflected emissions off the emitter.
Hearing becomes gradually less sensitive as frequency decreases, so for humans to perceive infrasound, the sound pressure must be sufficiently high. Although the ear is the primary organ for sensing low sound, at higher intensities it is possible to feel infrasound vibrations in various parts of the body.
Sound waves in air, in a tube. Sound waves in a solid experience a phase reversal (a 180° change) when they reflect from a boundary with air. [2] Sound waves in air do not experience a phase change when they reflect from a solid, but they do exhibit a 180° change when reflecting from a region with lower acoustic impedance. An example of this ...
Before extensive research on whale vocalizations was completed, the low-frequency pulses emitted by some species of whales were often not correctly attributed to them. Dr Payne wrote: "Before it was shown that fin whales were the cause [of powerful sounds], no one could take seriously the idea that such regular, loud, low, and relatively pure frequency tones were coming from within the ocean ...