An example sound output apparatus may include an input unit, an output unit, and a processor configured to perform first-filtering of a frequency band of an audio signal received through the input unit based on a sound pressure of the sound output apparatus, second-filtering of a frequency band of the first-filtered audio signal based on a frequency response characteristic of the sound output apparatus, adjust a loudness of the received audio signal based on a perception volume level of the second-filtered audio signal, and output the adjusted audio signal through the output unit.