Siren sounds are a type of warning sound used to alert people of danger or an emergency. The most common siren sound is a wailing noise, which is created by rapidly changing the pitch of the sound. This sound is often referred to as a 'WAIL' and is typically five letters long. Another common siren sound is a blare, which is a loud, continuous sound that is usually six letters long. Both of these sounds are used to alert people of potential danger and to signal them to take action.