A signal processing apparatus and method is disclosed by which a feature value of an audio signal such as the tempo can be detected with a high degree of accuracy. A level calculation section produces a level signal representative of a transition of the level of an audio signal. A frequency analysis section frequency analyzes the level signal. A feature value extraction section determines a tempo, a speed feeling and a tempo fluctuation of the audio signal based on a result of the frequency analysis of the level signal. The invention can be applied to an apparatus which determines, for example, a tempo from an audio signal.