TABLE II.
Mean spectral amplitudes, with standard deviations, of the brainstem FFR to the [da] stimulus presented in quiet and noise. Amplification is applied in cases of hearing loss.
| Condition 1. Unamplified [da] stimulus | Condition 2. Amplified [da] stimulus | ||
|---|---|---|---|
| Normal hearing mean amplitude (μV) (S.D.) | Hearing impaired mean amplitude (μV) (S.D.) | Hearing impaired mean amplitude (μV) (S.D.) | |
| Envelope (spectral FFT amplitudes of the FFR to added polarities) | |||
| Quiet | |||
| F0-ADD | 0.074 (0.029) | 0.079 (0.044) | 0.083 (0.056) |
| H2-ADD | 0.043 (0.034) | 0.056 (0.041) | 0.074 (0.039) |
| H3-ADD | 0.030 (0.017) | 0.043 (0.026) | 0.045 (0.020) |
| Noise | |||
| F0-ADD | 0.075 (0.029) | 0.078 (0.057) | 0.080 (0.045) |
| H2-ADD | 0.043 (0.033) | 0.072 (0.040) | 0.082 (0.037) |
| H3-ADD | 0.030 (0.017) | 0.047 (0.021) | 0.047 (0.018) |
| TFS (spectral FFT amplitudes of the FFR to subtracted polarities) | |||
| Quiet | |||
| H4-SUB | 0.019 (0.015) | 0.022 (0.012) | 0.018 (0.013) |
| H5-SUB | 0.011 (0.018) | 0.012 (0.007) | 0.012 (0.010) |
| H6-SUB | 0.008 (0.005) | 0.006 (0.005) | 0.008 (0.007) |
| Noise | |||
| H4-SUB | 0.020 (0.019) | 0.022 (0.014) | 0.018 (0.013) |
| H5-SUB | 0.010 (0.007) | 0.014 (0.010) | 0.012 (0.010) |
| H6-SUB | 0.007 (0.005) | 0.009 (0.008) | 0.008 (0.007) |