A new kind of police siren that emits low-frequency vibrations ... "Infrasound is low frequency sound energy that affects the nervous system and prolonged exposure can lead to progressive medical ...

Police officers were left "confused" by a bird when it convincingly mimicked the sound of the sirens on their cars. Thames Valley Police said staff initially thought their vehicles had developed a ...

A police inspector has told the BBC how he was the first to be tricked by a bird mimicking the sound of a siren. Simon Hills said the two-tone impression had officers believing a car was faulty at ...