Figure 1. Behavioral results. A, Spontaneous speech (overt narration). Normalized mean (solid line) and variance (dashed lines) of the EMG power spectrum with the 1/f trend regressed out are shown. Inset, the original individual spectra (n = 7) are displayed for reference. The arrowhead indicates the mean rate of spontaneous syllable (/pa/) repetition. B, Syllable production. The gray box represents the mean (± SD; n = 11) /pa/ syllable rate in spontaneous production. For the reproduction experiment, the black boxes illustrate the actual reproduction frequencies of /pa/ syllables (mean ± SD; n = 11) as a function of the target frequencies (0.8, 1.1, 1.5, 2, 2.8, 3.7, and 5). The dashed diagonal line indicates ideal compliance with the target rate.