"With the exception of Perry, none of the engineers listed on uBeam’s patents are still at the company, according to their LinkedIn profiles. What's more, uBeam engineers are said to feel as though they were being pressured by management to describe the technology in more optimistic terms than they were comfortable with."

No, 100 dB SPL is not a fundamental law of physics, but it's certainly a fundamental limit of human tolerance (it's about the same sound pressure as standing next to an operating jackhammer), and even if you can't hear it at ~20 kHz, any small animal in the vicinity will likely be tortured (seriously, PETA should take an interest in this technology). And since we're talking about investing in a consumer technology, any fundamental limit in human tolerance or even FDA guidance should be a deal breaker from a business perspective. My objection is that no one did such a sanity check before investing a large sum into this concept.

Yeah, I examined the video, too, with the same conclusion. It's comical that no one thought to measure the current, too, before dropping $10M on them.