I agree it was poorly written. I believe the intent was to say: A) We have recording from Cuba, therefore there's proof of ultrasonic noise. B) This noise we

I agree it was poorly written. I believe the intent was to say: A) We have recording from Cuba, therefore there's proof of ultrasonic noise. B) This noise we have is in the audible spectrum, but we have reason to suspect it's from the interaction of two ultrasonic frequencies that together produce a very whiney audible frequency C) Ultrasonic noise can be used for spying and voice-injection, so there's a potential motive for the US to use such technology at an embassy.