The Effects of Decreasing the Magnitude of Elevation-Dependent Notches in HRTFs on Median Plane Localization

A binaural experiment was conducted to investigate whether a necessary magnitude of pinna related spectral notches in HRTFs exist. Individual HRIRs were measured at 0°, 30°, and 60° in the median plane for three subjects. The original HRTFs were manipulated so that dominant spectral notches between 5 and 10 kHz were filled in two different degrees. Localization tests were carried out with each subject judging each stimulus condition 15 times in a randomized order. It was found that for the 30° and 60° sources, two subjects tended to perceive the image to move upwards as pinna related notches were reduced. For 0°, however, an increase in front-back confusion occurred as a result of notch magnitude manipulation.