Noise Reduction Calculator — Formula
## Noise Reduction Between Rooms
The noise reduction (NR) is the actual level difference between two rooms separated by a partition.
### Formula
**NR = TL + 10 log10(A / S)**
- *TL* = sound transmission loss of the wall (dB)
- *A* = total absorption in the receiving room (Sabine)
- *S* = area of the partition
If the receiving room is very absorbent (A > S), NR exceeds TL. If it is reverberant (A < S), NR is less than TL.
The noise reduction (NR) is the actual level difference between two rooms separated by a partition.
### Formula
**NR = TL + 10 log10(A / S)**
- *TL* = sound transmission loss of the wall (dB)
- *A* = total absorption in the receiving room (Sabine)
- *S* = area of the partition
If the receiving room is very absorbent (A > S), NR exceeds TL. If it is reverberant (A < S), NR is less than TL.
Esempio Risolto
Wall TL = 45 dB, wall area = 15 m2, receiving room absorption = 30 m2 Sabine.
- NR = TL + 10 log10(A/S)
- NR = 45 + 10 log10(30/15)
- NR = 45 + 10 log10(2)
- NR = 45 + 3.01 = 48.01 dB