- Twin Ultrasound Transducers create very focused sound
- Curved sound waves cannot be heard if you are not in the cute place
- Could be great in classrooms, exhibitions or vehicles
Wouldn’t it be nice if you could have all the benefits of headphones without having to bother with the headphones? That’s what a new technology that creates “audible enclaves” could one day deliver.
The technology comes from professor of acoustics Yun Jing at Pennsylvania State University, whose team has found a way to project sound so that only the intended listener can hear it. It is currently short range – approx. 1 m – and relatively quiet at 60 dB, but both range and volume need to be improved by using higher power transfers.
How do sound piano work?
Audio enclaves are made using ultrasonic waves that are higher frequency than the sound waves we can hear. Two waves are passed through acoustic lenses that bend them, creating a curved path for the waves to follow. These paths converge at the destination – that’s you.
The smart bit here is that every single wave is inaudible on its own, so no one hears anything unless they are in the sweet place where the two waves are in the right place for the listener’s ears – then they form something your brain can actually figure out.
The hope is that the technology could be used to deliver private sound in public places, such as in classrooms or at outdoor venues and possibly also inside vehicles.
This is not the first time we have been promised personalized directions. In 2016, Turtle Beach announced their Hypersound speakers who used transparent glass to create “very directional sound”. Promotional video is below.
Turtle Beach announced a partnership with the Chinese audio company Audfly in 2021, and the resulting FocusTound speakers demonstrate one of the disadvantages of the technology: Where normal speakers start at a double-digit low frequency (ie down to 20Hz), these directional speakers have a much higher starting point: 500Hz to 600Hz. It makes them good to speak, but not good for music.
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This technique probably does not remove all the need for the best wireless headphones, and may not work on anything like a plane where the surrounding noise is so high that you still need some of the best noise -canceling headphones – but imagine if you could change your TV to send audio that only you can hear with the touch of a button when the family goes to be, or imagine to hear interesting comment on a museum exhibition just by standing in the right place. Nothing headset is necessary – I like the sound of it (if I’m in the sweet place).
