): The A-weighted sound pressure level of speech at a 4-meter distance, indicating how much nearby surfaces reflect sound. Comfort Distance ( rCr sub cap C
): The average steady-state noise from HVAC or masking systems. Measurement Requirements INTERNATIONAL STANDARD ISO 3382-3 DIN EN ISO 3382 3 E 2021 02 pdf
The standard defines several single-number quantities to evaluate acoustic performance: Spatial Decay Rate of Speech ( D2,Scap D sub 2 comma cap S end-sub ): The A-weighted sound pressure level of speech
Lp,A,S,4mcap L sub p comma cap A comma cap S comma 4 m end-sub DIN EN ISO 3382 3 E 2021 02 pdf