An audio processing apparatus comprising: an acquisition unit configured to acquire metadata including position information indicative of a position of an audio object and sound image information configured from a vector of at least two or more dimensions and representative of an extent of a sound image from the position; a vector calculation unit configured to calculate, based on a horizontal direction angle and a vertical direction angle of a region representative of the extent of the sound image determined by the sound image information, at least one spread vector, each of which is indicative of a position in the region; and a gain calculation unit configured to calculate, based on the at least one spread vector, a gain of an audio signal supplied to a corresponding sound outputting unit of two or more sound outputting units positioned in proximity to the position indicated by the position information, characterized in that the gain calculation unit is configured to: calculate the gain for each of the at least one spread vector in regard to each of the sound outputting units, calculate an addition value of the gains calculated in regard to the at least one spread vector for each of the sound outputting units, quantize the addition value into a gain of two or more values for each of the sound outputting units, and calculate a final gain for each of the sound outputting units based on the quantized addition value. an acquisition unit configured to acquire metadata including position information indicative of a position of an audio object and sound image information configured from a vector of at least two or more dimensions and representative of an extent of a sound image from the position; a vector calculation unit configured to calculate, based on a horizontal direction angle and a vertical direction angle of a region representative of the extent of the sound image determined by the sound image information, at least one spread vector, each of which is indicative of a position in the region; and a gain calculation unit configured to calculate, based on the at least one spread vector, a gain of an audio signal supplied to a corresponding sound outputting unit of two or more sound outputting units positioned in proximity to the position indicated by the position information, characterized in that the gain calculation unit is configured to: calculate the gain for each of the at least one spread vector in regard to each of the sound outputting units, calculate an addition value of the gains calculated in regard to the at least one spread vector for each of the sound outputting units, quantize the addition value into a gain of two or more values for each of the sound outputting units, and calculate a final gain for each of the sound outputting units based on the quantized addition value. calculate the gain for each of the at least one spread vector in regard to each of the sound outputting units, calculate an addition value of the gains calculated in regard to the at least one spread vector for each of the sound outputting units, quantize the addition value into a gain of two or more values for each of the sound outputting units, and calculate a final gain for each of the sound outputting units based on the quantized addition value.