Method of improving three-dimensional sound reproduction enables more effective 3D sound processing to be achieved with minimisation of high frequency components of a virtual sound source positioned behind the ear

摘要

The method utilizes the single channel signal to produce left and right channel signals corresponding to a virtual sound source at a given direction in space relative to a preferred position of a listener. The space includes a forward hemisphere and a rearward hemisphere of a reference sphere (30), relative to the preferred position, and the information channels include cues for direction perception The method involves providing a two channel signal having the same single channel signal in the two channels. The two channel signal is altered by modifying both of the channels using one of several head response transfer functions to provide a right signal in one channel and a left signal in the other channel. A time delay is introduced between the channels corresponding to the inter-aural time difference for a signal coming from the given direction. The signals in both channels is filtered using a high frequency cut filter, in which the filter characteristics are settable according to the given direction of the virtual sound source. The amount of high frequency cut is at a maximum for virtual sound sources placed directly behind the preferred position of the listener, that is at a direction of azimuth of 180 degrees and elevation zero degrees relative to the preferred position of the listener (10). The amount of high frequency cut progressively decreases as the forward hemisphere is approached.