Distribution of hearing levels averaged across left and right ears (dB HL) in four age groups
| Frequency | Centile | Age (years) | |||
| 20–29 | 30–39 | 40–49 | 50–59 | ||
| 3 kHz | 10 | −5.0 | −2.5 | 0.0 | 2.5 |
| 25 | 0.0 | 0.0 | 2.5 | 7.5 | |
| Median | 0.0 | 2.5 | 7.5 | 11.3 | |
| 75 | 5.0 | 5.0 | 12.5 | 17.5 | |
| 90 | 10.0 | 10.0 | 20.0 | 25.8 | |
| 4 kHz | 10 | 0.0 | 0.0 | 3.3 | 7.5 |
| 25 | 0.0 | 2.5 | 7.5 | 12.5 | |
| Median | 5.0 | 5.0 | 12.5 | 17.5 | |
| 75 | 10.0 | 10.0 | 19.4 | 26.9 | |
| 90 | 17.5 | 15.0 | 27.5 | 35.0 | |
| 6 kHz | 10 | 0.0 | 0.0 | 5.0 | 7.5 |
| 25 | 5.0 | 5.0 | 10.0 | 12.5 | |
| Median | 10.0 | 7.5 | 13.8 | 21.3 | |
| 75 | 15.0 | 12.5 | 22.5 | 29.4 | |
| 90 | 20.0 | 17.5 | 35.0 | 37.5 | |
| n | 74 | 197 | 133 | 77 | |