2D to 3D ambience upmixing based on perceptual band allocation

3D multichannel audio systems employ additional elevated loudspeakers in order to provide listeners with a vertical dimension to their auditory experience. Listening tests were conducted to evaluate the feasibility of a novel vertical upmixing technique called “perceptual band allocation (PBA),” which is based on a psychoacoustic principle of vertical sound localization, the “pitch height” effect. The practical feasibility of the method was investigated using 4-channel ambience signals recorded in a reverberant concert hall using the Hamasaki-Square microphone technique. Results showed that the PBA-upmixed 3D stimuli were significantly stronger than or similar to 9-channel 3D stimuli in 3D listener-envelopment (LEV), depending on the sound source and the crossover frequency of PBA. They also significantly produced greater 3D LEV than the 7-channel 3D stimuli. For the preference tests, the PBA stimuli were significantly preferred over the original 9-channel stimuli.