Deviation Request ETSO-C139a#1 Aircraft Audio Systems and Equipment

Deviates from RTCA DO-214A section 2.6.2.1 a. and b. by using a Sound Pressure Level of 104 dB SPL if the microphone is linear and if the frequency responses curves in standard conditions are identical at both 104dB SPL and 94dB SPL levels.
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Deviates from RTCA DO-214A section 2.6.2.1 a. and b. by using a Sound Pressure Level of 104 dB SPL if the microphone is linear (within 1 dB from the linear approximation) and if the frequency responses curves in standard conditions are identical (within 1 dB) at both 104dB SPL and 94dB SPL levels.