The embassy in Havana cut its staff in half in 2017 after dozens of people complained of headaches, nausea and other ailments from hearing mysterious, penetrating high-pitched noises — believed to be an acoustic weapon — possibly from the Russians. But a fresh analysis of an audio recording made by US personnel in Cuba revealed that the source of the piercing din is the song of the Indies short-tailed cricket, known as Anurogryllus celerinictus, a study says.