Fig. 1.

Subcortical response of bilinguals (red) and monolinguals (black) to the speech sound [da] presented in multitalker babble. (A) Bilinguals show a larger auditory brainstem response relative to monolinguals. (B) Amplitudes of the individual component frequencies in the steady-state (60–180 ms) region of the response to [da] in multitalker babble. Thin lines represent 1 SEM. Inset in B displays the mean amplitude (±1 SE) of the fundamental frequency in quiet and in multitalker babble for bilinguals and monolinguals. For monolinguals, there is a decrease in the amplitude of the fundamental frequency (F0, 100 Hz) when the stimulus is presented in multitalker babble relative to when it is presented in quiet. In contrast, bilinguals show virtually no change in F0 amplitude between the two conditions. Asterisks represent significance levels: **P < 0.005, ***P < 0.0001.