Not a proof, but several years ago I found this [1] document from a FOIA request on "Bioeffects of Selected Nonlethal Weapon" and I found it interesting enough to save a copy. Specific section is "Incapacitating Effect: Microwave Hearing".

[1] https://legislature.mi.gov/documents/2013-2014/CommitteeDocu...

Edit: ocr-ed version here:

https://www.wired.com/images_blogs/dangerroom/files/Bioeffec...