Measurement And Analysis Of Spatial Position Perceptual Characteristics Of Binaural Cue

In order to achieve realistic 3D audio effects,you can increase the number of channels to achieve multi-channel digital audio system.However,the increase in the number of channels is accompanied by an increase in the amount of audio data,and in the case where the storage capacity is limited and the transmission bandwidth is limited,the reconstruction of 3D audio is inevitably reduced.Based on this,how to efficiently encode multichannel digital audio signals in order to use less bit rate to transmit the required data becomes one of the hotspots in 3D audio research.The traditional audio coding technique is based on the independent coding of a single channel,which will result in a waste of bandwidth as the number of channels increases.The spatial audio coding technique based on binaural cue is used to deal with the multi-channel original signal by downmixing technology.The hypocenter monaural signal and the spatial clue characterization of the sound space information are obtained,which are used to characterize the azimuth and sound image width of the sound source Including Interaural time difference(ITD),Interaural level difference(ILD)and Interaural correlation(IC),which can be used to signal the edge information.At the same time,at the receiving end,the decoder reduces the downmixed monaural signal into a multi-channel signal and restores the spatial parameters in the side information.It can be seen that the use of spatial coding technology for coding,the amount of data will be far less than the original signal information,reducing the storage space and bandwidth requirements,but also because the space to retain the spatial information parameters,the use of multi-channel Playback technology,you can guarantee the output of high-quality audio.Using the binaural cue to quantify the spatial characteristics of the sound,the relevant scholars have also measured and analyzed the binaural cue-sensing characteristics,mainly focused on the sensitivity of the binaural time difference and binaural intensity difference perception,that is,just to perceive the difference Notice Different,JND)values.The sound has three horizontal clues in the three-dimensional space,and the theoretical research shows that the binaural cue has the correlation with the azimuth angle of the sound,the head radius R and the sound velocity C.The researchers have tested the ITD and ILD values corresponding to the specific angles in the horizontal orientation,but the overall test point selection is less and lacks systematic perceptual analysis.Therefore,further testing and analysis must be done.Based on this,this thesis first uses single-frequency sinusoidal pure tone,the use of artificial head equipment in the silence environment to collect the horizontal direction of the 8 bands of sound data,the establishment of test audio sample library.Based on the spatial psychoacoustic design of the audiometry software,the ILD and ITD of the binaural cues were taken at 8 frequency bands in the low frequency band respectively.The sensed characteristics in the horizontal azimuth were tested,and the JND test method was obtained.The justification of the azimuth on the horizontal plane(Just Notice,JN).Finally,the obtained data are interpolated and fitted to obtain the three-dimensional surface and function relation of binaural cue and azimuth and frequency.