We investigate the effect of noise loading in a hybrid phase-sensitive amplifier system, analyzing the effect of noise beating between the signal and idler waves coupled in a parametric amplifier. Through analyzing input and output optical signal to noise ratios, we find that system performance of a phase-sensitive amplifier is 3 to 6 dB improved over a phase-insensitive amplifier, depending on the ratio of loaded noise power to that of vacuum fluctuations.