Voice Intelligibility is a requirement in the fire codes to provide voice messages that are able to be heard and understood. Recent additions to the fire codes have added important information defining the performance requirements of the speakers and the testing procedures to test the speakers’ performance.

Building owners concerned about the performance capabilities of their existing fire alarm speakers should perform audibility and intelligibility tests. Antal & Associates is capable of providing these tests and delivering a complete test record. 

Key Terminology
• Intelligibility Test - A test method used to predict how well speech is understood by a listener.
• Occupied Ambient Sound Pressure Level - The period of time when the building involved in the test is occupied and is reasonably close to having maximum background noise.
• Unoccupied Ambient Sound Pressure Level - The period of time when the primary occupants of the facility are not present, or when ambient noise is not at its highest level.