Azimuth effects on the Kemar Mannequin

The effect of head shadow and diffraction by the Kemar mannequin was explored with both pure-tone and pink-noise sound fields in an anechoic chamber. Polar recordings of 360° rotation of the mannequin were made for each 13 octave from 0.25 to 12.5 kHz with the point source on the same horizontal plane as the Zwislocki coupler in the mannequin's ear. Simultaneous magnetic tape recordings were transferred digitally to a computer programmed to compare the data with published human data. Comparisons were made for the full azimuth range for each frequency and for the full frequency range at each 15° of azimuth. Results shown that pink-noise data agrees closely with averaged human results [E.A.G. Shaw, J. Acoust. Soc. Am. 56, 1848–1861 (1974)]. Pure tone results show good correspondence with the same averaged human data at low and middle frequencies but show deviant peaks at higher frequencies. At least some of these variations appear to be related to detailed pinna geometry.