Mean audio output levels across conditions. The acoustic output data shows that participants produced /a/ more loudly than /a-a-a/ which they in turn produced more loudly than /a - a-a - a/. However, calibration of the acoustic stimuli ensured that the volume through the earphones was equivalent in both speak and listen tasks in each condition. Standard Error (±) shown in dashed line. Output shown as acoustic power in dB SPL (ambient baseline noise in the scanner room was 50 dB).