Disclosed is a signal processing apparatus including a surrounding sound signal acquisition unit, a NC (Noise Canceling) signal generation part, a cooped-up feeling elimination signal generation part, and an addition part. The surrounding sound signal acquisition unit collects a surrounding sound to generate a surrounding sound signal. The NC signal generation part generates a noise canceling signal from the surrounding sound signal. The cooped-up feeling elimination signal generation part generates a cooped-up feeling elimination signal from the surrounding sound signal. The addition part adds together the generated noise canceling signal and the cooped-up feeling elimination signal at a prescribed ratio.