Employee of the US Embassy injured brain after hearing “abnormal sound” in China

An employee of the US Embassy received a minor brain injury after hearing an “abnormal sound” while working in China.
The US State Department issued a warning on the health of its citizens in China, which describes a mysterious case.
“A US government employee working in China recently reported anomalous sensations after he heard strange sounds, and then felt pressure on the brain and fainted,” the statement said.
The employee received the necessary medical assistance and his health is in satisfactory condition. The reason for this “sound attack” is not currently installed.