Aeronautic Indicators
Aeronautic Indicators are useful for cabin noise evaluation and they compute the Speech Interference Levels in dB SIL3, dB SIL4, dB PSIL and the sound level dB(G).
Speech Interference Level in dB SIL3 corresponds to the arithmetic mean of levels in octaves 1000, 2000 and 4000 Hz.
Speech Interference Level in dB SIL4 corresponds to the arithmetic mean of levels in octaves 500, 1000, 2000 and 4000 Hz.
Preferred-octave Speech interference Level in dB PSIL corresponds to the arithmetic mean of levels in octaves 500, 1000 and 2000 Hz.
Sound Level in dB(G) measures the weighted physical level for infrasound components of the power spectrum (centered on 20 Hz). See standard ISO 7196 for more details.