Question

Suppose the analog signal shown here is from a music program on the radio. How do you think the music would be affected by the noise when you listen to it on the radio? Explain.

Answer 1

Any random electrical noise added to the transmitted analog waveform turns up as unwanted sound when you listen. In the time domain the noise is superimposed on the music waveform; after demodulation you hear the music plus the noise. That usually shows up as background hiss (high‑frequency random fluctuations), occasional crackles or pops (spikes), and a loss of clarity and detail. Quiet passages are affected most (the noise is more noticeable and can mask soft tones), while very loud parts can partly mask the noise.

If it’s AM radio the noise (an amplitude disturbance) is directly translated into audible interference, so static is very noticeable. FM is less sensitive to pure amplitude noise but still produces hiss and distortion of fine detail when the signal‑to‑noise ratio is poor. In short: the music will sound noisier and less clear; the exact character depends on the noise spectrum and the modulation method.