1.2.12-9 Intensity of Speech Presentation

Speech signal intensity should be clearly audible for the expected ambient noise environment.

Additional Information:
For critical messages, speech should be at least 20 dB above the speech interference level at the operating position of the intended receiver. Signal to noise ratios should be at least 5:1. Audio signal power should be approximately 300 milliwatts at the listener ear. Speech signals should fall within the range of 200 to 6100 Hz.