TECHNICAL BULLETIN: Noise Levels
Date: 14th June 2006
Below are details of the noise pressure levels across the spectrum for some NR noise ratings.
Sound pressure Levels at mid frequencies (Hz)
| NR | 31.5Hz | 63Hz | 125Hz | 250Hz | 500Hz | 1000Hz | 2000Hz | 4000Hz | 8000Hz | Typical Applications |
| NR45 | 86 | 71 | 61 | 54 | 48 | 45 | 42 | 40 | 38 | Restaurant |
| NR40 | 83 | 67 | 57 | 49 | 44 | 40 | 36 | 35 | 33 | General Office |
| NR35 | 79 | 63 | 52 | 45 | 39 | 35 | 32 | 30 | 28 | Private Offices |
| NR30 | 76 | 59 | 48 | 40 | 34 | 30 | 27 | 25 | 23 | Cinemas |
| NR25 | 72 | 55 | 44 | 35 | 29 | 25 | 22 | 20 | 18 | Concert Halls |
| NR20 | 69 | 51 | 39 | 31 | 24 | 20 | 17 | 14 | 13 | Broadcasting and Recording studios |
| NR15 | 66 | 47 | 35 | 26 | 19 | 15 | 12 | 9 | 7 | Audio Labs |