Siren, Police - Police Car: Ext: Two Tone Siren, Stationary, From Engine, Police Vehicles & Sirens - song and lyrics by Sound Effects Library | Spotify
7 Interesting IC 555 Siren and Alarm Circuits - Homemade Circuit Projects
Freesound - SFXsource.com-free-police-siren-sound-effect.mp3 by SFXsource.com