Figure 2.

Cross-phase comparisons of responses to contrasting speech sounds /ga/ and /ba/ in musicians (left) and nonmusicians (right) for 3 age groups. For each cross-phaseogram, phase differences are plotted as a function of frequency over time. Phase shift in radians is indicated by color, with warm colors indicating phase-lead (/ga/ before /ba/) and cool colors indicating phase-lag (/ba/ before /ga/). Analyses were performed for periods corresponding to the formant transition (15–45 ms) and steady-state vowel (60–170 ms), as notated by dotted lines. Bar graphs indicate average phase shifts for each age group in the frequency range that distinguishes /ba/ from /ga/ up to the noise floor for each age group (adults: 900–1400 Hz, children: 900–1500 Hz, preschoolers: 900–1350 Hz). Musicians have greater phase shifts than nonmusicians in responses to the formant transition. The steady-state vowel is consistent between stimuli and responses show an appropriate lack of phase shift in both musicians and nonmusicians (*P < 0.05, **P < 0.01, ***P < 0.005).