“[T]he intelligence community is in the lead on that [investigation]. They have launched a large-scale investigation into the potential causes. They are actively examining a range of hypotheses, but they have not made a determination about the cause of these incidents, or who is responsible,” Psaki said at a press briefing.
Earlier in the day, President Joe Biden signed into law a measure that provides compensation to the US diplomatic personnel whose health has been affected by the so-called “Havana Syndrome.”
US diplomats were first diagnosed with the Havana syndrome in Cuba in 2016 and then in China in 2018. The diplomats said they experienced piercing sounds that have caused longer-term health effects. US diplomats in Russia, Tajikistan, Austria and several African countries have also reported having experienced Havana syndrome symptoms, including nausea and dizziness.
The veracity of the “Havana Syndrome” incidents has been recently challenged by a new study completed by the JASON advisory group, a scientific advisory body, at the request of the US State Department in September. The researchers concluded that no single energy source is capable of producing both the recorded audio/video signals, and bring about the reported health effects. Moreover, the JASON group believes the sounds are biological in origin and most likely come from local crickets' mating calls.
The US government initially blamed Russia for what it said were "acoustic attacks," but the allegations have been dismissed by Moscow as absurd. In July, CIA Director William Burns said Russia may be responsible for the incidents, but the US government lacks proof to have a final determination.