Magnitude spectra (orange solid lines) produced by the LDREPS in the occluded-ear simulator and measured with the ER-10B+ microphone. Each panel shows the averaged spectrum for a pure-tone signal at a level above its reference threshold. The signal frequency, f₁, is indicated in the bottom left corner of the panel. For comparison, the spectrum of a background noise measurement is also shown (dark gray solid line). In addition, the reference thresholds are shown as a black dashed line. The frequency spectra are limited to the frequency range from 3 Hz to 300 Hz.