Figure 1.

Virtual reverberant stimuli. A, Geometry of the virtual room. Reverberant binaural room impulse responses (BRIRs) were simulated using the image method for a source positioned at 0° azimuth either 1.5 m (“moderate” reverberation, magenta) or 3 m (“strong” reverberation, red) away from the model spherical head (gray). B, Example BRIR (right channel, strong reverberation). The direct sound is followed by superimposed reflections with approximately exponential energy decay. Detail reveals individual early reflections. C, Time course of modulation depth at the ear in reverberant and anechoic stimuli. Anechoic stimulus modulation depth is nearly 1 throughout the entire stimulus duration, whereas reverberant stimulus modulation depth decays after stimulus onset to reach a plateau by 250 ms. D, Binaural room modulation transfer functions (MTFs) describe the attenuation of amplitude modulation between a source and each ear due to reverberation. MTFs were computed in the steady-state part of the reverberant stimuli (see Materials and Methods). Anechoic MTFs (blue) are flat at 0 dB attenuation. Moderate (magenta) and strong (red) reverberant MTFs are <0 dB and frequency dependent. MTFs for left (solid lines) and right (dashed lines) ears were similar at most modulation frequencies.