The way that the system output is related to the system input for different frequencies is called the frequency response of the system. The frequency response is the relationship between the system input and output in the Fourier Domain .
We can use Matlab to do this using either a direct calculation or the function freqs(). >
Frequency response is a property of a system (e.g. and audio amplifier) that processes signals, there typically being and input signal to the system and a resulting output or response signal from the system. The frequency response of a system can usually be determined by comparing the output signal to the input signal in the frequency domain. Give this perspective, signals do not have a frequency response as implied in the question. Perhaps the question needs to be rephrased, as stated it seems nonsensical.