direction of arrival (DoA) unit vector estimation circuitry that estimates a DoA unit vector that indicates a direction of a sound source for each of a plurality of frequency bins of a signal arriving from the sound source using the signal recorded by a microphone array;

calculation circuitry that selects, from among the estimated DoA unit vectors, as a representative DoA unit vector, a DoA unit vector in one frequency bin in which a sum of differences between the DoA unit vector and DoA unit vectors of other frequency bins is a minimum, and calculates a frequency weighting factor for each of the plurality of frequency bins based on the selected representative DoA unit vector; and

estimation circuitry that selects, from among the estimated DoA unit vectors, DoA unit vectors based on the calculated frequency weighting factor, and estimates the direction of arrival of the signal using the selected DoA unit vectors.