): The reduction in sound pressure level (dB) when the distance from a speaker is doubled. Speech Level at 4 Meters (
): The distance from a speaker where the Speech Transmission Index (STI) falls below 0.50, the point at which concentration starts to improve. Background Noise Level ( Lp,A,Bcap L sub p comma cap A comma cap B end-sub DIN EN ISO 3382 3 E 2021 02 pdf
(often cited as the 2022 international version) is the primary standard for measuring room acoustic parameters in unoccupied open-plan offices . Unlike Part 2, which focuses on temporal decay (reverberation), Part 3 focuses on spatial decay , or how sound levels drop as you move away from a speaker. Key Acoustic Parameters ): The reduction in sound pressure level (dB)
): The average steady-state noise from HVAC or masking systems. Measurement Requirements INTERNATIONAL STANDARD ISO 3382-3 Unlike Part 2, which focuses on temporal decay
): A newer metric that has largely replaced "privacy distance" in recent revisions, indicating the distance at which speech becomes comfortable for others. Distraction Distance ( rDr sub cap D