Interesting. I wonder how much power they are running? How loud would it be if it were in the human hearing range. (Can dogs stand to be in the room?)

@carbon-unit: the paper referenced at the bottom of the article says "the transducer operated at a frequency of 25230 Hz with a displacement amplitude of 15 μm" and the acoustic pressure just below the sphere ranges from 1 to 8 kPa. A quick back-of-the-envelope (literally!) calculation tells me that this would be over 1000 dB (referenced to 20 μPa), which would not just be unpleasant but deafening. Do not try this at home :)
Those with more experience in acoustics may like to check that and correct me if necessary.

Well, being ultrasonic it is WAY above the range of hearing where we would get to hear anything, you can see the person in the film setting the styrofoam ball into place with bare hands, So, you can deduce a few things, one, while a lot of energy is going into it, it is way faster than our ears can perceive, it did no damage to his hands nor, apparently, to the ball itself. I think it is a matter of very carefully timed sets of rotation of the vibratory pattern, an offset of each of the three transducers seen, and so it is held in place by the counteracting forces being manipulated much faster than it can respond with any noticeable effect. Very nice, and yes, much better than levitating droplets of liquids or various size and power of magnets.

Acoustics is powerful stuff.
http://www.generalfusion.com/

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Most commercially available ultrasonic devices in the 25kHz range are about 700-1000 watt, so it again, can't be much above 160-180 These devices, the three horns... are going to be fed by standard commercial gear, in my estimation. which means that 700-1000 watts per horn.

If it was making that much heat I would expect to see some kind of optical distortions. The roof of your car at most gets 1000 watts per meter square and you can definitely see the air shimmering over it.

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Since the video blinks the information too quickly for most humans.
sphere diameter: 50 mm
sphere mass: 1.46 g
transducer frequency: 25 kHz
transducer diameter: 20 mm
(Sphere is polystyrene - low density styrofoam)

They could get better "lift" with shaped waveforms too. Like a Parenthesis shape '( ' hitting the sphere repeatedly, but I don't think their transducers have a bored cup at the end as they appear quite flat.