TABLE I.
Overall and octave band levels for all conditions at all angles. Values are given in dB SPL at 1 m.
| Angle | Overall level | 125 Hz | 250 Hz | 500 Hz | 1 kHz | 2 kHz | 4 kHz | 8 kHz | 16 kHz |
|---|---|---|---|---|---|---|---|---|---|
| Normal speech | |||||||||
| 0 | 62.0 | 50.2 | 56.0 | 57.4 | 55.0 | 51.2 | 46.3 | 46.4 | 38.0 |
| 15 | 62.4 | 51.0 | 56.7 | 58.0 | 54.8 | 50.2 | 44.6 | 45.4 | 37.9 |
| 30 | 61.8 | 50.1 | 55.8 | 57.5 | 54.3 | 51.1 | 45.6 | 44.7 | 37.5 |
| 45 | 61.5 | 49.8 | 55.5 | 57.4 | 53.6 | 50.4 | 44.7 | 43.3 | 35.7 |
| 60 | 61.1 | 49.6 | 55.2 | 57.3 | 53.5 | 48.7 | 42.4 | 40.6 | 33.6 |
| 75 | 60.5 | 49.1 | 54.4 | 56.7 | 53.6 | 46.5 | 41.0 | 39.4 | 32.9 |
| 90 | 59.8 | 48.6 | 53.7 | 55.8 | 53.4 | 44.2 | 40.0 | 37.7 | 30.8 |
| 105 | 58.8 | 48.1 | 52.9 | 54.6 | 52.5 | 43.6 | 37.3 | 34.9 | 27.9 |
| 120 | 57.5 | 47.5 | 52.1 | 53.0 | 50.4 | 43.3 | 33.6 | 31.4 | 23.8 |
| 135 | 56.4 | 47.1 | 51.5 | 51.9 | 48.0 | 41.9 | 31.8 | 28.6 | 20.2 |
| 150 | 55.8 | 46.7 | 51.1 | 51.4 | 47.1 | 38.2 | 29.6 | 24.9 | 16.3 |
| 165 | 55.8 | 46.6 | 51.0 | 51.4 | 48.1 | 36.2 | 25.3 | 21.4 | 14.5 |
| 180 | 56.0 | 46.6 | 50.9 | 51.5 | 48.7 | 38.1 | 27.4 | 20.1 | 11.3 |
| Female speech | |||||||||
| 0 | 61.3 | 39.0 | 55.6 | 56.7 | 54.8 | 51.1 | 45.0 | 46.7 | 39.2 |
| 15 | 61.6 | 39.7 | 56.3 | 57.3 | 54.6 | 50.1 | 43.4 | 45.6 | 39.0 |
| 30 | 61.0 | 38.8 | 55.4 | 56.8 | 54.0 | 51.0 | 44.2 | 45.0 | 38.6 |
| 45 | 60.6 | 38.4 | 55.0 | 56.6 | 53.4 | 50.2 | 43.2 | 43.7 | 36.5 |
| 60 | 60.2 | 38.1 | 54.7 | 56.5 | 53.4 | 48.3 | 40.8 | 41.1 | 34.4 |
| 75 | 59.6 | 37.5 | 54.0 | 55.8 | 53.4 | 46.0 | 39.2 | 40.1 | 33.9 |
| 90 | 58.9 | 36.9 | 53.2 | 54.9 | 53.2 | 43.8 | 38.3 | 38.4 | 32.1 |
| 105 | 57.9 | 36.4 | 52.5 | 53.7 | 52.2 | 43.3 | 35.6 | 35.5 | 29.1 |
| 120 | 56.5 | 35.8 | 51.7 | 52.2 | 50.1 | 43.1 | 31.6 | 31.8 | 24.9 |
| 135 | 55.3 | 35.4 | 51.2 | 51.1 | 47.7 | 41.8 | 30.4 | 29.1 | 21.2 |
| 150 | 54.8 | 35.1 | 50.9 | 50.6 | 46.9 | 38.2 | 28.4 | 25.4 | 17.3 |
| 165 | 54.8 | 34.9 | 50.8 | 50.6 | 47.8 | 35.8 | 23.9 | 22.0 | 15.4 |
| 180 | 55.0 | 34.9 | 50.7 | 50.6 | 48.5 | 38.1 | 26.5 | 19.8 | 11.8 |
| Male speech | |||||||||
| 0 | 62.7 | 54.0 | 56.2 | 58.0 | 55.0 | 51.0 | 47.5 | 45.6 | 34.7 |
| 15 | 63.1 | 54.9 | 57.0 | 58.7 | 54.9 | 50.0 | 45.9 | 44.5 | 34.1 |
| 30 | 62.6 | 54.0 | 56.1 | 58.2 | 54.4 | 50.9 | 46.9 | 43.8 | 34.0 |
| 45 | 62.3 | 53.7 | 55.8 | 58.1 | 53.6 | 50.3 | 46.2 | 42.0 | 33.1 |
| 60 | 62.0 | 53.6 | 55.5 | 58.1 | 53.3 | 48.8 | 43.9 | 39.0 | 31.0 |
| 75 | 61.4 | 53.0 | 54.7 | 57.5 | 53.3 | 46.8 | 42.6 | 37.2 | 29.0 |
| 90 | 60.7 | 52.6 | 53.9 | 56.6 | 53.2 | 44.4 | 41.6 | 35.5 | 25.5 |
| 105 | 59.7 | 52.1 | 53.1 | 55.4 | 52.4 | 43.5 | 39.0 | 32.9 | 22.3 |
| 120 | 58.4 | 51.5 | 52.1 | 53.6 | 50.4 | 43.0 | 35.3 | 29.7 | 19.0 |
| 135 | 57.3 | 51.1 | 51.4 | 52.4 | 47.8 | 41.5 | 33.2 | 26.9 | 16.0 |
| 150 | 56.8 | 50.8 | 50.9 | 52.1 | 46.9 | 37.5 | 30.7 | 23.0 | 11.7 |
| 165 | 56.8 | 50.7 | 50.6 | 52.1 | 47.9 | 36.3 | 26.6 | 19.0 | 10.7 |
| 180 | 56.9 | 50.6 | 50.6 | 52.2 | 48.4 | 37.5 | 28.2 | 20.0 | 9.5 |
| Soft speech | |||||||||
| 0 | 54.8 | 46.9 | 50.7 | 48.6 | 43.3 | 38.8 | 38.9 | 41.8 | 32.2 |
| 15 | 55.4 | 47.7 | 51.5 | 49.3 | 43.2 | 37.8 | 37.4 | 41.0 | 31.8 |
| 30 | 54.7 | 46.8 | 50.5 | 48.7 | 42.7 | 38.7 | 38.4 | 40.7 | 31.0 |
| 45 | 54.3 | 46.5 | 50.2 | 48.5 | 42.2 | 38.0 | 37.6 | 39.4 | 29.3 |
| 60 | 54.0 | 46.3 | 49.9 | 48.4 | 42.2 | 36.4 | 35.6 | 36.8 | 27.6 |
| 75 | 53.4 | 45.8 | 49.2 | 47.8 | 42.3 | 34.4 | 34.4 | 35.5 | 27.0 |
| 90 | 52.6 | 45.2 | 48.5 | 46.8 | 42.1 | 32.3 | 33.7 | 33.7 | 25.1 |
| 105 | 51.8 | 44.7 | 47.8 | 45.7 | 41.2 | 31.4 | 31.0 | 31.1 | 22.2 |
| 120 | 50.8 | 44.0 | 47.0 | 44.2 | 39.1 | 31.1 | 27.3 | 27.5 | 18.4 |
| 135 | 50.0 | 43.6 | 46.5 | 43.1 | 36.6 | 29.8 | 25.5 | 24.9 | 15.1 |
| 150 | 49.7 | 43.3 | 46.2 | 42.6 | 35.8 | 26.2 | 23.3 | 21.5 | 11.7 |
| 165 | 49.5 | 43.1 | 46.0 | 42.5 | 36.7 | 24.1 | 18.7 | 18.2 | 10.5 |
| 180 | 49.6 | 43.1 | 46.0 | 42.5 | 37.3 | 25.9 | 20.6 | 16.7 | 8.9 |
| Loud speech | |||||||||
| 0 | 73.8 | 55.4 | 64.0 | 68.5 | 69.1 | 66.3 | 61.5 | 54.7 | 47.6 |
| 15 | 73.6 | 55.9 | 64.5 | 68.9 | 68.7 | 65.2 | 59.7 | 53.6 | 47.3 |
| 30 | 73.4 | 55.1 | 63.7 | 68.5 | 68.1 | 66.1 | 60.6 | 53.0 | 47.1 |
| 45 | 72.8 | 54.6 | 63.3 | 68.4 | 67.3 | 65.4 | 59.6 | 51.2 | 45.3 |
| 60 | 72.2 | 54.2 | 62.9 | 68.2 | 66.8 | 63.8 | 57.3 | 48.2 | 42.8 |
| 75 | 71.5 | 53.5 | 62.1 | 67.5 | 66.8 | 61.7 | 55.5 | 46.9 | 42.2 |
| 90 | 70.7 | 52.9 | 61.2 | 66.6 | 66.6 | 59.3 | 54.2 | 45.2 | 39.9 |
| 105 | 69.6 | 52.3 | 60.4 | 65.3 | 65.7 | 58.2 | 51.7 | 42.5 | 36.8 |
| 120 | 68.0 | 51.7 | 59.5 | 63.6 | 63.6 | 57.8 | 47.5 | 39.0 | 32.3 |
| 135 | 66.5 | 51.2 | 58.8 | 62.5 | 61.1 | 56.6 | 45.5 | 35.9 | 28.6 |
| 150 | 65.8 | 51.0 | 58.5 | 62.2 | 60.4 | 53.1 | 43.9 | 32.4 | 25.0 |
| 165 | 66.1 | 50.9 | 58.3 | 62.3 | 61.5 | 51.1 | 39.7 | 28.6 | 21.4 |
| 180 | 66.6 | 51.1 | 58.5 | 62.6 | 62.3 | 53.1 | 41.9 | 28.0 | 18.4 |
| Singing | |||||||||
| 0 | 73.9 | 55.8 | 64.2 | 70.8 | 67.7 | 63.3 | 59.9 | 50.2 | 42.3 |
| 15 | 74.1 | 56.5 | 64.8 | 71.4 | 67.6 | 62.4 | 58.3 | 49.3 | 42.1 |
| 30 | 73.7 | 55.5 | 63.9 | 70.9 | 67.0 | 63.0 | 59.6 | 48.6 | 41.8 |
| 45 | 73.3 | 55.0 | 63.5 | 70.8 | 66.5 | 62.1 | 58.6 | 46.9 | 40.3 |
| 60 | 73.0 | 54.8 | 63.1 | 70.7 | 66.6 | 60.4 | 56.3 | 44.1 | 38.5 |
| 75 | 72.5 | 54.1 | 62.3 | 70.0 | 66.8 | 58.4 | 54.9 | 42.7 | 37.6 |
| 90 | 71.7 | 53.5 | 61.4 | 69.0 | 66.6 | 56.1 | 53.8 | 40.6 | 34.8 |
| 105 | 70.6 | 52.9 | 60.6 | 67.8 | 65.7 | 55.3 | 50.7 | 37.9 | 31.5 |
| 120 | 69.0 | 52.4 | 59.7 | 66.2 | 63.8 | 55.0 | 47.1 | 34.4 | 27.7 |
| 135 | 67.6 | 52.1 | 59.0 | 65.0 | 61.3 | 53.9 | 46.2 | 32.0 | 24.2 |
| 150 | 66.8 | 51.7 | 58.5 | 64.5 | 60.1 | 50.4 | 43.9 | 28.5 | 20.2 |
| 165 | 66.8 | 51.6 | 58.2 | 64.4 | 60.8 | 47.7 | 38.4 | 25.2 | 18.6 |
| 180 | 67.2 | 51.4 | 58.2 | 64.5 | 61.7 | 49.9 | 41.3 | 23.4 | 15.7 |
| /s/ | |||||||||
| 0 | 58.5 | 32.7 | 31.0 | 28.4 | 28.4 | 36.1 | 51.1 | 57.0 | 48.2 |
| 15 | 57.6 | 33.3 | 31.6 | 28.9 | 28.1 | 34.8 | 49.9 | 56.1 | 47.8 |
| 30 | 57.4 | 32.7 | 30.9 | 28.5 | 27.8 | 36.1 | 51.1 | 55.4 | 47.4 |
| 45 | 56.0 | 32.3 | 30.5 | 28.3 | 26.9 | 35.7 | 50.5 | 53.8 | 45.7 |
| 60 | 53.4 | 32.2 | 30.1 | 28.2 | 26.2 | 34.8 | 48.0 | 50.9 | 43.7 |
| 75 | 52.1 | 31.9 | 29.7 | 27.9 | 26.2 | 34.0 | 46.7 | 49.5 | 42.5 |
| 90 | 50.6 | 31.9 | 29.5 | 27.4 | 26.5 | 31.6 | 46.0 | 47.7 | 39.9 |
| 105 | 48.0 | 31.8 | 29.2 | 26.8 | 26.1 | 29.7 | 43.3 | 44.9 | 36.9 |
| 120 | 44.9 | 31.4 | 28.7 | 25.6 | 24.7 | 29.2 | 39.9 | 41.4 | 33.0 |
| 135 | 42.7 | 31.5 | 28.6 | 25.0 | 23.3 | 28.3 | 37.4 | 38.5 | 29.2 |
| 150 | 40.4 | 31.4 | 28.5 | 24.7 | 22.3 | 25.6 | 34.8 | 34.8 | 24.4 |
| 165 | 38.0 | 31.0 | 28.1 | 24.0 | 21.8 | 23.1 | 30.1 | 30.6 | 20.9 |
| 180 | 38.4 | 31.2 | 28.4 | 24.5 | 22.4 | 23.7 | 31.3 | 30.5 | 18.1 |
| /sh/ | |||||||||
| 0 | 57.2 | 34.0 | 30.6 | 28.0 | 29.1 | 49.2 | 54.9 | 50.8 | 37.7 |
| 15 | 55.7 | 34.5 | 31.1 | 28.7 | 28.8 | 47.5 | 53.3 | 49.4 | 37.0 |
| 30 | 56.3 | 33.9 | 30.6 | 28.4 | 28.5 | 48.9 | 54.4 | 48.2 | 36.9 |
| 45 | 55.4 | 33.5 | 30.2 | 28.1 | 27.3 | 48.4 | 53.6 | 46.2 | 35.7 |
| 60 | 53.6 | 33.2 | 29.9 | 27.9 | 26.2 | 47.7 | 51.5 | 43.4 | 32.8 |
| 75 | 52.8 | 33.0 | 29.6 | 27.6 | 26.3 | 46.7 | 50.8 | 41.9 | 30.9 |
| 90 | 51.4 | 33.1 | 29.6 | 27.4 | 26.7 | 44.2 | 49.7 | 40.1 | 27.8 |
| 105 | 49.2 | 33.1 | 29.4 | 26.8 | 26.6 | 42.2 | 47.3 | 38.2 | 24.8 |
| 120 | 46.6 | 32.6 | 28.6 | 25.6 | 25.3 | 41.3 | 43.7 | 34.9 | 21.3 |
| 135 | 45.2 | 32.7 | 28.6 | 25.1 | 24.1 | 40.9 | 41.6 | 32.5 | 18.0 |
| 150 | 43.1 | 32.6 | 28.4 | 24.7 | 23.2 | 37.5 | 39.6 | 28.3 | 14.5 |
| 165 | 40.2 | 32.0 | 27.7 | 23.7 | 22.4 | 34.7 | 35.2 | 24.5 | 13.5 |
| 180 | 41.6 | 32.4 | 28.3 | 24.3 | 22.8 | 36.2 | 37.5 | 23.5 | 12.1 |
| /f/ | |||||||||
| 0 | 44.0 | 28.8 | 27.1 | 28.5 | 32.2 | 33.9 | 33.2 | 39.2 | 38.7 |
| 15 | 43.6 | 28.5 | 27.1 | 28.8 | 31.8 | 33.0 | 31.7 | 38.9 | 38.7 |
| 30 | 44.0 | 28.9 | 27.0 | 28.5 | 31.3 | 34.6 | 33.1 | 38.3 | 39.4 |
| 45 | 42.9 | 28.2 | 26.3 | 28.3 | 30.0 | 34.3 | 32.9 | 36.3 | 38.4 |
| 60 | 40.9 | 27.2 | 25.4 | 28.0 | 28.6 | 33.5 | 31.3 | 33.6 | 35.5 |
| 75 | 40.2 | 27.6 | 25.4 | 27.6 | 28.5 | 32.4 | 31.0 | 32.5 | 33.8 |
| 90 | 39.3 | 28.5 | 25.9 | 27.3 | 28.9 | 30.3 | 30.7 | 31.1 | 31.3 |
| 105 | 38.3 | 28.7 | 26.0 | 26.6 | 28.8 | 29.1 | 28.6 | 29.0 | 28.4 |
| 120 | 36.9 | 28.1 | 25.2 | 25.3 | 27.3 | 28.7 | 25.4 | 26.4 | 24.6 |
| 135 | 36.3 | 28.4 | 25.4 | 24.7 | 25.5 | 27.9 | 23.7 | 24.3 | 21.0 |
| 150 | 35.6 | 28.3 | 25.3 | 24.3 | 24.3 | 25.5 | 21.7 | 21.2 | 16.6 |
| 165 | 34.4 | 27.3 | 24.3 | 23.6 | 24.0 | 23.1 | 18.6 | 17.9 | 15.2 |
| 180 | 35.2 | 28.2 | 25.3 | 24.3 | 24.9 | 23.6 | 18.1 | 16.1 | 13.2 |
| /th/ | |||||||||
| 0 | 43.8 | 33.2 | 32.1 | 29.9 | 28.8 | 31.0 | 31.9 | 36.7 | 39.5 |
| 15 | 43.6 | 33.8 | 32.7 | 30.3 | 28.7 | 30.0 | 30.7 | 36.4 | 38.8 |
| 30 | 43.9 | 33.2 | 32.1 | 29.9 | 28.5 | 31.7 | 32.2 | 36.7 | 39.5 |
| 45 | 43.4 | 32.9 | 31.6 | 29.5 | 27.7 | 31.8 | 31.9 | 35.7 | 39.0 |
| 60 | 42.1 | 32.6 | 31.2 | 29.2 | 27.0 | 31.0 | 30.6 | 33.2 | 37.2 |
| 75 | 41.5 | 32.5 | 30.9 | 28.9 | 27.1 | 30.1 | 30.2 | 32.2 | 36.2 |
| 90 | 40.8 | 32.8 | 30.8 | 28.5 | 27.4 | 28.7 | 30.1 | 31.3 | 33.5 |
| 105 | 40.0 | 32.8 | 30.4 | 27.9 | 27.1 | 27.6 | 28.5 | 29.6 | 30.8 |
| 120 | 38.9 | 32.5 | 29.7 | 26.8 | 25.8 | 27.1 | 25.8 | 27.0 | 27.5 |
| 135 | 38.6 | 32.6 | 29.6 | 26.5 | 24.8 | 26.4 | 24.2 | 25.1 | 24.5 |
| 150 | 38.1 | 32.5 | 29.4 | 26.3 | 24.0 | 24.4 | 22.1 | 22.2 | 20.0 |
| 165 | 37.3 | 32.0 | 28.8 | 25.6 | 23.2 | 22.3 | 19.0 | 19.2 | 17.8 |
| 180 | 37.7 | 32.4 | 29.1 | 26.1 | 23.5 | 22.1 | 18.5 | 17.4 | 15.1 |
| Ambient noise a | |||||||||
| 0 | 27.8 | 15.1 | 5.6 | 5.4 | 7.0 | 8.7 | 10.4 | 11.0 | 10.3 |
| 15 | 28.5 | 16.2 | 5.7 | 5.9 | 7.8 | 8.8 | 8.6 | 8.2 | 6.8 |
| 30 | 27.9 | 15.0 | 5.8 | 4.8 | 6.6 | 8.4 | 10.0 | 10.6 | 9.3 |
| 45 | 27.8 | 14.8 | 6.4 | 5.3 | 6.8 | 8.6 | 10.3 | 11.1 | 10.1 |
| 60 | 28.1 | 15.0 | 6.7 | 5.8 | 7.8 | 9.5 | 10.7 | 11.1 | 10.1 |
| 75 | 28.2 | 15.9 | 5.7 | 4.9 | 6.4 | 8.2 | 9.5 | 9.9 | 8.6 |
| 90 | 28.5 | 16.4 | 5.1 | 5.1 | 6.6 | 8.4 | 10.2 | 10.9 | 10.0 |
| 105 | 28.5 | 15.9 | 5.9 | 5.6 | 7.2 | 9.0 | 10.6 | 11.2 | 10.5 |
| 120 | 28.6 | 15.9 | 6.5 | 5.7 | 7.1 | 8.8 | 10.1 | 10.5 | 9.7 |
| 135 | 28.9 | 16.6 | 6.6 | 5.2 | 6.2 | 7.8 | 9.5 | 10.6 | 10.5 |
| 150 | 29.0 | 16.8 | 6.1 | 5.7 | 7.3 | 9.0 | 10.7 | 11.4 | 10.6 |
| 165 | 29.3 | 17.1 | 6.2 | 4.4 | 6.9 | 9.4 | 11.7 | 13.7 | 15.4 |
| 180 | 29.1 | 17.2 | 3.5 | 2.7 | 4.4 | 6.8 | 9.1 | 10.6 | 10.6 |
a
Ambient noise levels are reported as exact measured values. As all other values reported here were extrapolated to 1 m from the mouth using the inverse square law, accurate comparison to ambient noise levels requires extrapolation back to 60 cm (an increase of ∼4.44 dB).