1. A method of implementing a 3-dimensional sound, the method comprising: adding an inter-aural time delay (ITD) to at least one input sound signal; multiplying the at least one input sound signal having the ITD added by a principal component weight to generate at least one weighted signal; and filtering the at least one weighted signal by a low-order model of each of a plurality of basis vectors extracted from a head related transfer function (HRTF), wherein the plurality of basis vectors comprise one direction-independent mean vector and a plurality of directional basis vectors, wherein the plurality of basis vectors are extracted from the HRTF by Principal Component Analysis (PCA) in time-domain, wherein the direction-independent mean vector is a vector that is not determined based on a position of a sound source and each of the plurality of directional basis vectors is a vector that is determined based on a position of a sound source, and wherein each of the plurality of basis vectors is modeled by an IIR (infinite impulse response) filter model to generate the low-order model of each of the plurality of basis vectors.