An elevation coding method for auditory displays

Abstract

This paper describes an alternative approach to elevation coding in an auditory display delivered through headphones. Objects in auditory display are presented as sound sources. Direction dependent cues for auditory display construction are most effectively presented by individualised head-related transfer functions (HRTFs), while generalised HRTFs give satisfactory results only in the azimuth. Since measurements of individualised HRTFs are impractical, we propose an alternative method for coding elevation. This method requires some time for the listener to adapt to it. The learning process can be shortened significantly if the coding is similar to natural human perception of sound elevation. To test human capability of distinguishing between different sounds, several sound sets were created and presented to test subjects. Five sound sets with the best resolution were then used to create auditory display of a graphical user interface (GUI). Test subjects were able to learn this display in relatively short time, which justifies the method and gives opportunity for further research.