What does a frequency response curve primarily involve?

A frequency response curve primarily involves the assessment of filters, highlighting how a system responds to different frequencies in terms of gain and phase shift. This curve illustrates the output amplitude relative to a range of input frequencies, effectively depicting how different frequencies are amplified or attenuated by the filter.

In the context of signal processing, filters are crucial as they determine the behavior of a system regarding various frequencies. The curve provides valuable insight into the filter characteristics, such as cutoff frequencies and the bandwidth of operation, enabling engineers and technicians to understand how the system will handle signals in different frequency ranges.

The other options are related to electronic systems but do not directly correlate with the primary function of a frequency response curve. Sensitivity relates more to how responsive a system is to input signals, duration pertains to the length of time a signal is processed, and input impedance refers to the resistance encountered by a signal entering a system. While these factors can affect the overall performance of a circuit, they do not encapsulate the main purpose of a frequency response curve as filters do.