Figure 4.

Multiunit data analysis and results. A: an example recording (Table 1: bird 1, recording 1, electrode 3) of multiunit EMG activity from VS muscle. The signal (pink shaded regions) and noise (blue shaded regions) regions were used to calculate the SNR (see methods). B: example recording (Table 1: bird 1, recording 1, electrodes 1, 2, and 3) of the multiunit SNR values for an extended continuous recording in three vocal muscles. All SNR values for each complete breath cycle were averaged across 1 min. C: the SNR of CNTFs (birds 1–8) in vocal muscles ranged from 8.4 ± 3.7 to 43.6 ± 3.3 and was significantly higher (one-way ANOVA, P = 0.032) compared with SSW (birds 9–11) with SNR of 6.2 ± 1.2 to 7.9 ± 1.7. CNTF, carbon nanotube fiber; SNR, signal-to-noise ratio; SSW, stainless-steel wire; VS, ventral syringeal.