We demonstrated the following: 1) The amplitude of the reference signal may have a significant impact on correlation and phase-synchrony values, and even a small change in reference amplitude can lead to a significant change on correlation and phase-synchrony values; 2) reference signal power may have a significant impact on MSC value, and even a small change of reference signal power can significantly change MSC. This point shows that the conclusion drawn in [36] is not true in general and is limited to the assumptions required to obtain the upper bound of (12); and 3) even if reference signal power is greater than the power of nonreferential signals, the effect at a given frequency can be small.
