When the input noise is the single-peak Gaussian noise, the noise can improve the signal correlation only for the sub-threshold signal, i.e. subthreshold stochastic resonance (SR) exists.

• 当输入噪声为单峰高斯噪声时，输入信号在阈下时噪声才能改善信号的相关性，即随机谐振现象存在。