Fig. 1.

Single-neuron responses to clean and distorted speech. (A) Effect of stimulus distortions on the average firing rate of neurons. Each point indicates the average response of a single neuron to clean (horizontal axis) and distorted speech (vertical axis). Correlations between responses in each pair of conditions appear over each plot. Most neurons did not exhibit a significant change in their firing rate, and the correlations between conditions were significant (***P < 0.001, t test). (B) Histogram of neural spike rates in clean and distorted conditions. Horizontal bars at the top show mean and SD for each condition. (C) Joint histogram of instantaneous neural responses at fine time scales (20-ms bins) to clean speech and to the same speech samples in noise (r = 0.36, 0.40, and 0.39, P < 0.001, t test). (D) Normalized MSE difference between neural responses to clean and distorted speech for different bin sizes.