5/4/2023 0 Comments Speed of sound underwaterScientists use sound to send and retrieve information from undersea robots, buoys, and other ocean tools, and they are always working hard to improve sound-based technology. The neat thing about sound is that scientists can transform information into sound waves and send it over great distances. Sound travels in the form of waves, as light does. Scientists studying the ocean use much more sophisticated methods to communicate under water using sound. That’s why scuba divers usually use hand signals to communicate with each other. Although a pool conversation (if you can call it that) proves that sound travels through water, it also proves that our vocal chords don’t transmit sound that well in the water. Have you ever tried to talk to a friend in a pool-while you were both under water? If so, whatever you said probably sounded like an inaudible string of garbly “gloughs” that made you giggle so hard you had to pop up for a breath of air. Images above based on NOAA's Ocean Explorer These two waves have the same amplitude but different frequencies. These two waves have the same frequency but different amplitudes. In this example of a sound wave, the period of one cycle of this wave is 0.5 seconds, and the frequency of this wave is 2 cycles per second or 2 Hertz (Hz). The basic components of a sound wave are frequency, wavelength, and amplitude. The study is published in the journal Hearing Research.īy Andrei Ionescu, Earth.Under water, it's difficult to communicate! “The results tell us that humans have a reduced ability to determine the direction of sounds underwater, thus confirming that human hearing is not adapted to work well underwater,” he concluded. In water, the speed of sound is four times greater, and the time differences are much smaller,” explained Dr. This is not so strange, because we are trained to react to the small time differences between the ears, which are due to the speed of sound in air. “In air we can determine the sound direction within a few degrees, but in water there is an up to 90 degrees error margin. However, the sense of hearing is not only about being able to pick up sounds, but also about determining the direction of the sound – which, for humans, remains very difficult underwater. While previous studies hypothesized that human hearing underwater is mediated by bone conduction, with sound waves causing vibrations in the skull, this new study argues that resonance in the enclosed air in the middle ear actually amplifies the sound and makes the ear more sensitive – a phenomenon common to cormorants, turtles, and frogs too. In fact, the threshold at 500 Hz is in line with how well animals such as cormorants and seals hear underwater,” said Dr. “It is 26 dB lower than hypothesized in previous studies, so we must conclude that humans hear significantly better underwater than previously reported by science. “Common to all these scientific studies is that they all find hearing thresholds that are higher than the thresholds we have found in our new study,” said study co-author Jakob Christensen-Dalsgaard, an expert in animal hearing at SDU.īy measuring the underwater hearing thresholds of seven participants, the experts found that the average threshold was 71 dB at a frequency of 500 Hz.
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