Quality Control of Measuring for Head-Related Transfer Functions of Chinese Pilots

A specified procedure was conducted for measuring HRTF database. The experimenters were trained to reduce the tester errors. Pilot as participator was sat in (x, y, z) coordinates with the origin at midpoint of bitragion on his Frankfurt plane same as polar coordinates of (r, ϕ, θ), keeping his posture to reduce the testee errors during each block of the experiment. The test–retest checks were arranged at (ϕ, 0°), (ϕ, 180°) and (ϕ, 360°) for data quality control. Other strategies were done such as the division of the experiment into 13 blocks and schedules of rest by turns to reduce human errors from fatigue. Three testers were trained with dummy head MK2B, and 63 male pilots were measured in hemi-anechoic room to build CHNAF HRTF database. The results were found that the tester error was about 0.29 dB of ILD and –0.75° azimuth deviation, the 2.0 dB of ILD was acceptable alarm threshold for binaural spatial symmetry because of pilots posture change, and the data quality of the CHNAF HRTF database was well validated.