Consider a frequency domain sketch of a signal g(t): Frequency Spectrum 10 20 30 Frequency f/kHz Figure Q5 40 50 (a) Give a mathematical description of the signal g(t). (b) If the above signal is heard by a human, sketch the spectrum that corresponds to the signal perceived by the brain. State your assumptions clearly. (c) Consider a high-pass filter with cutoff frequency equals to 30 kHz. Sketch the filter characteristic H(f) of this high-pass filter. State your assumptions clearly. (d) Sketch the spectrum at the filter output when signal x(t) is passed through the filter H(f).