Individual HRTF measurements for accurate obstacle sonification in an electronic travel aid for the blind

The article presents a study of virtual sound source localization errors with the use of personalized head related transfer functions (HRTFs) in light of design of an electronic travel aid for the blind. The proposed device for aiding visually disabled individuals in independent mobility requires presentation of spatial sounds, which lead to the need to construct a system for efficient individual HRTF measurement. Measurements were performed for 15 sighted and blind individuals. Verification trials limited to the frontal hemisphere have shown that the localization of virtual sound sources can be performed with accuracy reaching average errors of 6.36deg in azimuth and 9.47deg in elevation.