We spend our lives immersed in sound. Our ears are very sensitive detectors, letting us tune in to tiny air vibrations, and telling us what's going on around the corner, under our feet and even a mile or two away. But we still only detect a tiny fraction of the sound that's out there.
The Ultrasonics and Underwater Acoustics team in the Institute of Sound and Vibration Research specializes in some of the sounds we can't experience directly. The sound we study is either underwater or it's too high-pitched for us to hear. And we do much more than just listen in to this hidden world - we study what it can do, what it can tell us and how to use it in new technologies.
For example, very high-pitched (ultrasonic) sound waves in water can be used as acoustic tweezers. We're learning how to move human cells or bacteria in a very precise way, which can be put to use growing new tissues to replace diseased body parts. It can also push microbes towards detectors, helping us locate and identify different types of bacteria.
Aquatic animals generally get much more information about their world from sound than from light, because sound travels really well underwater but light is quickly absorbed. Understanding how fish respond to different sounds will help us minimize disruption to fish populations when big engineering projects are undertaken, and could also help us guide fish away from hazards like water pump intakes. Whales and dolphins rely on sound, and some of us work on understanding the calls and how they could be using really clever techniques to interpret their world.
Underwater bubbles are almost invisible if you're looking with light, but if you're looking with sound they are very conspicuous. That turns out to be useful in all sorts of ways. Our researchers have combined bubbles and a special sound source to make a really effective cleaning device. The bubbles from breaking waves help the oceans to breathe, and we use sound to monitor that process and to help understand weather and climate. We're also interested in all the other things that bubbles can do, for example speeding up chemical reactions, improving ultrasound scans and acting as sound absorbers.
Lastly, underwater and ultrasonic sounds are fantastically useful tools in the human world too. We work with industry on leak detection, crack detection, medical imaging and monitoring environmental noise.
We think that this world of hidden sound is both fascinating and important. We currently work with marine archeologists, chemists, oceanographers, zoologists and many others, and we're always interested in new topics. You can find out more about the projects listed above from the links or directly from the researchers pages.
