Interaural Time Difference (ITD) and Interaural Level Difference (ILD) are the main cues used by the human auditory system to localize sound sources on the horizontal plane. To explore the relationship between ITD, ILD, and the perceived azimuth, a study was conducted to measure and analyze the localization effects on the horizontal plane by combining ITD and ILD. Pure tones were used as sound sources in the experiment. For each of the three different frequency bands, 25 combinations of ITD and ILD test values were selected. These combinations were used to process the perceived sound from directly in front of the listener (pure tone signals collected using an artificial head in an anechoic chamber). The tests were conducted using the 1up/2down and 2AFC (two-alternative forced-choice) psychophysical testing methods. The results showed that the perceived azimuth at 350 Hz and 570 Hz was generally higher than at 1000 Hz. Additionally, the perceived azimuth at 350 Hz and 570 Hz was similar under certain combinations. The experimental data and conclusions can provide foundational data and theoretical support for efficient compression of multi-channel audio.
