TABLE 1. Hearing loss and pure tone thresholds across age.
Mean (s.d.) hearing level at each frequency, interaural symmetry, and number and proportion of children in each hearing category from 6 – 11 years. Categories were Symmetric and Asymmetric, Minimal and Mild hearing loss, and Normal hearing. 1kHz and 4 kHz mean thresholds (dB HL, averaged across ears) for all children at each age are shown at bottom of table.
| Category/Age | Mean HL dB (s.d.) |
Mean Asym dB (s.d.) |
6y.o. | 7y.o. | 8y.o. | 9y.o. | 10y.o. | 11y.o. | Total | |
|---|---|---|---|---|---|---|---|---|---|---|
| 1 kHz | 4 kHz | |||||||||
| Min Symm | 17.6(4.0) | 15.3(2.0) | 4.7 | n=26 | 41 | 30 | 26 | 34 | 17 | 174 |
| Min Asymm | 16.2(4.9) | 14.2(3.2) | 15.5 | 16 | 11 | 10 | 15 | 8 | 11 | 71 |
| Mild Symm | 26.4(5.6) | 25.7(4.4) | 4.7 | 14 | 12 | 12 | 6 | 8 | 1 | 53 |
| Mild Asymm | 26.5(6.2) | 26.0(4.5) | 22.1 | 9 | 3 | 6 | 5 | 8 | 4 | 35 |
| Norm hearing | 8.3(4.7) | 6.1(3.8) | 3.5 | 148 | 203 | 185 | 231 | 224 | 133 | 1124 |
| Total children | 213 | 270 | 243 | 283 | 282 | 166 | 1457 | |||
| % Minimal | 19.7% | 19.3 | 16.5 | 14.5 | 14.9 | 16.9 | 16.8 | |||
| % Mild | 10.8 | 5.6 | 7.4 | 3.9 | 5.7 | 3.0 | 6.0 | |||
| % Normal | 69.5 | 75.2 | 76.1 | 81.6 | 79.4 | 80.1 | 77.1 | |||
| 1 kHz mean threshold | 11.9 | 10.6 | 10.9 | 10.1 | 10.0 | 9.3 | ||||
| 4 kHz mean threshold | 8.6 | 6.2 | 6.0 | 5.0 | 5.8 | 5.3 | ||||