The Pearson correlation of the AUW and the amplitude difference for the RLN and EBSLN, when injury data were included. (A) rRLN =0.563, P=0.001. (B) rEBSLN =0.800, P<0.001. AUW, area under waveform; RLN, recurrent laryngeal nerve; EBSLN, external branch of the superior laryngeal nerve.