They are related in that it's just a case of mass hysteria.
The media reports say the symptoms were "subtle and vague, but abnormal, sensations of sound and pressure" that lasted a year. That sounds entirely consistent with a psychiatric explanation.
People working in embassies aren't somehow immune to psychiatric issues (and may in fact be more likely to experience things like this, due to the pressures of their work).
I do also like the psyops disinfo theory - as stated elsewhere in this thread, suppose it was some other less respected nation that was making claims that their diplomats were victims of a mysterious sonic weapon. The claim would be poorly received. Personally there's a deeply appealing irony in the mass credulity being something like an even more massive mass hysteria.
Here is some evidence linking tinnitus to psychiatric disorders:
https://www.ncbi.nlm.nih.gov/pubmed/16844885
"A close association between tinnitus and psychiatric disorders has been demonstrated".
So is the original allegation in the article. I'm saying that psychiatric explanation fits the facts better. If you have any evidence to the contrary, feel free to post it...
Do you have something against a psychiatric explanation?