An audio signal processing device comprising: an audio signal processing unit configured to perform signal processing on an audio signal; a sound volume setting receiving unit configured to receive a sound volume set value; a sound volume measuring unit configured to measure a sound volume at a listening position; a level detection unit configured to detect a level of an input signal, the input signal being the audio signal input to the signal processing unit; wherein: the audio signal processing unit is configured to perform a loudness correction which increases a level of the audio signal in a prescribed frequency range as the sound volume set value decreases; the sound volume measuring unit is configured to measure sound volumes corresponding to plural respective sound volume set values at the listening position; the audio signal processing unit is configured to set a level adjustment amount to be used in performing the loudness correction on the basis of the level of the input signal detected by the level detection unit, the sound volume set value received by the sound volume setting receiving unit and the measurement sound volumes measured by the sound volume measuring unit, such that if the audio signal level varies to a large extent in a single piece, a phenomenon can be prevented that high-frequency components and low-frequency components are less audible when the sound volume is small. an audio signal processing unit configured to perform signal processing on an audio signal; a sound volume setting receiving unit configured to receive a sound volume set value; a sound volume measuring unit configured to measure a sound volume at a listening position; a level detection unit configured to detect a level of an input signal, the input signal being the audio signal input to the signal processing unit; wherein: the audio signal processing unit is configured to perform a loudness correction which increases a level of the audio signal in a prescribed frequency range as the sound volume set value decreases; the sound volume measuring unit is configured to measure sound volumes corresponding to plural respective sound volume set values at the listening position; the audio signal processing unit is configured to set a level adjustment amount to be used in performing the loudness correction on the basis of the level of the input signal detected by the level detection unit, the sound volume set value received by the sound volume setting receiving unit and the measurement sound volumes measured by the sound volume measuring unit, such that if the audio signal level varies to a large extent in a single piece, a phenomenon can be prevented that high-frequency components and low-frequency components are less audible when the sound volume is small. the audio signal processing unit is configured to perform a loudness correction which increases a level of the audio signal in a prescribed frequency range as the sound volume set value decreases; the sound volume measuring unit is configured to measure sound volumes corresponding to plural respective sound volume set values at the listening position; the audio signal processing unit is configured to set a level adjustment amount to be used in performing the loudness correction on the basis of the level of the input signal detected by the level detection unit, the sound volume set value received by the sound volume setting receiving unit and the measurement sound volumes measured by the sound volume measuring unit, such that if the audio signal level varies to a large extent in a single piece, a phenomenon can be prevented that high-frequency components and low-frequency components are less audible when the sound volume is small.