Emergency Planet

A massive protest march was organised in Hong Kong on June 16. During the protest march, an ambulance carrying patient got stuck, but as soon as the protesters noticed the vehicle after hearing its siren, they made way for it. The entire incident was captured on the camera.

Footage of the tornado going through downtown and toppling the court house copula-Spire.

here are two STANDARD sounds of an electronic siren used on ambulances, but manufacturers vary even these standard sounds somewhat. The two standard sounds are wail and yelp. Wail is gradual increase and decrease in pitch. Yelp is a much more rapid increase and decrease in pitch. Generally, wail is used when going through a straight-away, mid-block, while yelp is used most often at intersections or coming upon congestion. Different manufacturers will often add other sounds, but some areas may ban the use of these other sounds, despite them being available in the siren control head. The reason these sounds are banned is due to the fact that they may not be interpreted as a siren by someone that is deaf at certain frequencies. Wail and yelp pass through many frequencies as the pitch goes up and down.