Comments on HRTFs measured with blocked ears
HRTFs introduced in this paper were measured with blocked ears. This
means that the subjects' ears were blocked by rigid earplugs made by
an expert (medical doctor) in otolaryngology so as to fit the shape of
the entrances of the subjects' ears. Methods for the calibration due to
differences in subjects and listening conditions (free-field and
headphone listening) were discussed by Møller et al.
Møller indicated that
the HRTFs measured with blocked ears reflect less individuality than
those measured with open ears, which are regarded as the normal
measurement condition. Moreover, transfer function from the entrance of
an ear to the eardrum involves much inidivisuality, and it makes the
calibration of free-field to headphone listening condition difficult.
Assuming the use of appropriate headphone, Møller suggested that
HRTFs measured with blocked ears are useful for calibration required in
those occasions. As for the appropriate headphone for binaural
listening, please refer to the discussion by Møller et
- Henrik Møller, "Fundamentals of binaural technology,"
Applied Acoustics, 36, 171-218(1992).
- Henrik Møller, Dorte Hammershøi, Clemen Boje Jensen
and Michael Friis Sørensen, "Tranfer characteristics of
headphones measured on human ears," J. Audio Eng. Soc.,
- Henrik Møller, Clemen Boje Jensen, Dorte Hammershøi
and Michael Friis Sørensen, "Design criteria for
headphones," J. Audio Eng. Soc., 43(4),