Measurement And Analysis Of Perceptual Characteristic Of Interaural Level Difference

With the rapid development of computer and communication technology, as well as the constant expansion of the field of digital audio applications, people’s requirements for audio quality have become higher. Thus, the speed of rapid development of 3D audio technology is promoted. In the wireless communication transmission, the data transmission rate has been very restricted due to the limited bandwidth resources. So reducing the number of data of audio coding is needed.Based on the spatial hearing theory, Spatial audio coding represents the sound source with mono signals and spatial parameters in encoder, and is synthesized in decoder. The basic information of the rebuilt sound field is derived from single channel signal, and the position and the size of spatial images are controlled by spatial parameters. Therefore, the spatial parameter is the core of spatial audio encoding. Binaural cues are composed of Interaural Time Difference(ITD), Interaural Level Difference(ILD) and Interaural correlation(IC). They are also important spatial parameters in spatial audio coding. Humans are able to localize a sound source in the space by binaural cues. Currently, the spatial audio coding technology is mainly used to determine the position of the sound source with the three binaural cues. Compared with traditional stereo coding, spatial audio coding can achieve higher coding gain and the quality of audio is the same as before. Besides, the audio takes up little storage space and saves bandwidth.This paper only researches the perceptual characteristics of ILD, measures the just-noticeable difference(JND) of ILD by subjective listening tests, and analyzes JNDs gained from the experiment by mathematical fitting method. Also, this paper draws a JND-frequency-direction of three-dimensional surface and provides a better theoretical basis for spatial audio coding technology.