FIGURE 2.

Global spectral amplitude (GSA) of FFR. (A) GSA spectra of the FFR. (B) GSA of the F0 component. (C) GSA of the H2 component. GSA is a reference-independent measure of strength of multichannel FFRs, representing the variance of the Fourier-transformed data across channels. The FFR in response to each stimulus has clear spectral peaks at the fundamental frequency (F0) and the second harmonics (H2). The strength of both F0 and H2 components significantly exceeds noise floor, suggesting good signal quality. Binaural stimulations lead to significantly larger GSA than monaural stimulations, suggesting the capability of this measure in reflecting FFR strength. Triangles point to the frequencies of stimulus F0s and twice F0s. Error bars refer to ±SEM.