In the absence of LMAN, bilateral ablation of HVC subregions does not produce a general disruption of syllable acoustic structure. A, In the presence of LMAN, bilateral damage to medial HVC results in a complete loss of syllable acoustic structure (compare with spectrograms in Fig. 2). B, In the absence of LMAN, bilateral damage that flanks but does not include HVC has a minimal effect on syllable acoustic structure (compare with spectrograms in Fig. 6). C, In the absence of LMAN, bilateral damage to medial HVC has a minimal effect on syllable acoustic structure (compare with spectrograms in Fig. 7). D, In the absence of LMAN, bilateral damage to central HVC has a minimal effect on syllable acoustic structure. E, In the absence of LMAN, bilateral damage to lateral HVC results in omission of some syllables (C, D) but has minimal effect on the acoustic structure of remaining syllables (A, B, compare with spectrograms in Fig. 7).