A Study on the Derivation of Transfer Functions for Sound Image Localization Using Stereo Earphones

Seven algorithms for using stereo headphones to obtain the sound localization transfer function (SLTF) are presented. The SLTF consists of three transfer functions, each being derived by the impulse response measuring method. Two evaluation measures for more precise SLTF values are adopted: the calculation time and the subjective assessment score. To assess SLTF precision, the term of numerical calculation error is introduced. The SLTF calculation time depends on the number of multiplications, and the scheme offering the fewest multiplications, and the scheme offering the fewest multiplications is found. Subjective assessment tests are carried out using the paired comparison method of Scheffe. The tests show the superiority of two of the seven methods.