Table 2.
Auditory brainstem response (ABR) results at three points of the study.
| Age | |||||||
|---|---|---|---|---|---|---|---|
| 2 months | 7 months | 10 months | |||||
| NF (n = 9) | FD (n = 10) | NF (n = 9) | FD (n = 9) | NF (n = 9) | FD (n = 5) | ||
| ABR1 threshold (dB SPL) | Click | 16 ± 1 | 17 ± 1 | 16 ± 1 | 18 ± 1 | 24 ± 1 | 24 ± 3 |
| 8 kHz | 22 ± 1 | 25 ± 0 | 23 ± 1 | 23 ± 1 | 44 ± 4 | 43 ± 1 | |
| 16 kHz | 21 ± 1 | 25 ± 2 | 24 ± 1 | 25 ± 0 | 43 ± 5 | 43 ± 3 | |
| 20 kHz | 21 ± 1 | 25 ± 0 | 29 ± 2 | 27 ± 1 | 43 ± 2 | 41 ± 1 | |
| 28 kHz | 23 ± 1 | 27 ± 1 | 28 ± 1 | 28 ± 1 | 40 ± 2 | 39 ± 1 | |
| 40 kHz | 28 ± 1 | 30 ± 2 | 32 ± 1 | 29 ± 1 | 39 ± 2 | 38 ± 1 | |
| Peak latencies1 (ms) | Wave I | 1.42 ± 0.01 | 1.33 ± 0.02 | 1.29 ± 0.04 | 1.35 ± 0.02 | 1.39 ± 0.02 | 1.34 ± 0.04 |
| Wave II | 2.42 ± 0.03 | 2.36 ± 0.02 | 2.18 ± 0.04 | 2.31 ± 0.02 | 2.36 ± 0.03 | 2.31 ± 0.07 | |
| Wave III | 3.17 ± 0.04 | 2.99 ± 0.05 | 2.87 ± 0.06 | 2.97 ± 0.03 | 3.17 ± 0.06 | 3.20 ± 0.09 | |
| Wave IV | 4.07 ± 0.03 | 3.93 ± 0.04 | 3.90 ± 0.05 | 3.93 ± 0.02 | 4.06 ± 0.03 | 3.99 ± 0.04 | |
| Interpeak latencies1 (ms) | I–II | 1.00 ± 0.02 | 1.02 ± 0.01 | 0.98 ± 0.02 | 0.96 ± 0.01 | 0.97 ± 0.02 | 0.97 ± 0.03 |
| I–IV | 2.65 ± 0.03 | 2.60 ± 0.03 | 2.61 ± 0.03 | 2.58 ± 0.02 | 2.68 ± 0.02 | 2.65 ± 0.03 | |
| II–IV | 1.65 ± 0.02 | 1.57 ± 0.02 | 1.72 ± 0.02 | 1.62 ± 0.02 | 1.70 ± 0.02 | 1.68 ± 0.05 | |
| Amplitude1 (nV) | Wave I | 857 ± 88 | 729 ± 95 | 869 ± 217 | 835 ± 44 | 553 ± 39 | 424 ± 57 |
| Wave II | 1474 ± 153 | 1285 ± 128 | 922 ± 147 | 1035 ± 73 | 961 ± 79 | 964 ± 90 | |
| Wave III | 150 ± 44 | 188 ± 52 | 278 ± 66 | 288 ± 65 | 192 ± 35 | 224 ± 60 | |
| Wave IV | 1278 ± 175 | 1105 ± 104 | 1227 ± 210 | 1449 ± 106 | 746 ± 94 | 797 ± 129 | |
Hearing parameters were measured during the whole study in the normal (NF) and folate deficient (FD) dietary groups, although only three key points of the experiment that correspond to the start, 5 and 8 months of diet administration (2, 7 and 10 months of age) are shown. 1mean ± SEM.