Analyzing notch patterns of head related transfer functions in CIPIC and SYMARE databases

The sensation of elevation in binaural audio is known to be strongly correlated to spectral peaks and notches in HRTFs, introduced by pinna reflections. In this work we provide an analysis methodology that helps us to explore the relationship between notch frequencies and elevation angles in the median plane. In particular, we extract the portion of the HRTF due to the presence of the pinna and we use it to extract the notch frequencies for all the subjects and for all the considered directions. The extracted notch frequencies are then clustered using the K-means algorithm to reveal the relationship between notch frequencies and elevation angles. We present the results of the proposed analysis methodology for all the subjects in the CIPIC and SYMARE HRTFs databases.