Transfer functions of headphones are measured to verify that they meet certain requirements or to determine what equalization may make them meet an ideal target curve. The present study compares six headphones by physical measurements at the eardrums of six individuals and on a dummy head. For headphone transfer functions we are interested in the variability in the produced sound pressure at the eardrum across individuals, the similarity between dummy head and real-ear measurements, the agreement with the diffuse-field design target and, finally, the prevalence of all-pass phase
