What good is an announcement over a mass communications system if you can’t understand the message? Voice alarm systems play an important role in alerting occupants and the clarity of that message can contribute to safe evacuation procedures. Many issues can affect the clarity of speech transmission through a voice actuated fire alarm or mass communications system including background noise, reverberation and distortion. The NFPA 72 Annex E (National Fire Alarm Code) has introduced standards that require voice alarm systems to meet specific levels of speech intelligibility.
The Verifier is a special type of sound level meter which offers simplified methodology for measurement of Speech Transmission Index-Public Address (STI-PA), to ensure voice actuated fire alarms, mass communications and PA systems are clearly heard and understood in an emergency.