4. Expressions of acoustic performance for buildings and construction elements

Regulatory texts dealing with the acoustic characteristics of buildings use "single values" to express requirements.

For acoustic insulation between rooms, or between the outside space and a room, we find D _nAT (dB(A)), D _nTA (dB), D _nAT,route (dB(A)), D _nTA,tr (dB), R _A .

For impact noise, the sound levels not to be exceeded in reception areas are expressed as L _nAT (dB(A)) or ${\text{L}}_{\text{nTw}}^{\prime }$ (dB)....