Voice evacuation systems are becoming increasingly common as more and more jurisdictions are requiring them in their fire codes. However, designing a system that has good intelligibility is much more difficult than simply using ordinary sounders.

Listed below are links to basic voice evacuation system design information.

Important Topics
- Relationship between Power and Sound Output
- Tips Voice Evacuation System Intelligibility
- SP200 Frequency Response(chart)
- Total Harmonic Distortion (chart)

Listing Agencies Input
- A Word about Speaker Output ratings
- UL Speaker Output at Various Tap Settings (chart)

Sound Pressure Calculators
- Sound Pressure Loss with Distance
- Sound Pressure Level from Two Speakers

Polar Plot Data for System Sensor Speakers.