They are surely talking about a device. It is possible to focus sound to specific location.. there are multiple ways, short distance and longer ones.

I would guess someone has lead that person down the garden path, possibly to test their knowledge or common sense, but there's also the rise of the anti science cult [a] in the last 10 or so years - and some people have attained positions they should not occupy who might seriously believe such things

Consider 1, reading minds. If there was any tech that was any better than lie detection ... a scanning type system that was even good enough to hint at a rough notion of non conforming ideas [b] within minds -it would have been used and within the present government agencies and government, there would have been large changes in the power structure - more than anything reported so far.

By 2, remove memories - I have assumed specific / particular things, otherwise broadly, brain trauma and some drugs will do that.

[a] - rise of flat earth beliefs ... magnetism can be disrupted / dissolved with water ...

[b] and not intent by asking the right questions while under observation