Variability in the characterization of the headphone transfer-function

In simulations of virtual acoustic space, stimuli are filtered with HRTFs and presented over headphones. An equalization filter is specified to compensate for the spurious coloration introduced by the headphone delivery system on the stimulus at the listener’s eardrum. The purpose of this letter is to report the variability in the response of supra-aural headphones arising from the positioning of the headphone cushion during normal usage. The headphone responses were obtained on the KEMAR acoustical mannequin. It is shown that the variability in the measurements due to headphone cushion placements makes it difficult to specify a compensation filter for canceling the headphone characteristics. This makes the stimulus waveform at a listener’s eardrum unpredictable and could have an important consequence on the perceptual adequacy of virtual displays.