For non-compatible, public-use buildings, an average sound level of ______ dBA is the nominal design objective.

• A. 35
• B. 40
• C. 45
• D. 50

Answer: (C)

Interior noise levels in non-compatible public-use buildings are guided by a nominal design objective of 45 dBA. This uses A-weighting to reflect how humans perceive loudness, and the 45 dBA target serves as a practical balance between keeping speech intelligibility and occupant comfort while remaining achievable with typical building envelope and mechanical design. Values lower than this would require more aggressive sound attenuation and higher costs, while values around 50 dBA would allow more noticeable noise intrusion, reducing comfort and speech clarity in public spaces.