Oldfield S R, Parker S P
Perception. 1984;13(5):601-17. doi: 10.1068/p130601.
The acuity of azimuth and elevation discrimination was measured under conditions in which the cues to localisation provided by the pinnae were removed. Four subjects localised a sound source (white noise through a speaker) which varied in position over a range of elevations (-40 degrees to +40 degrees) and azimuths (0 degree to 180 degrees), at 10 degrees intervals, on the left side of the head. Pinna cues were removed by the insertion of individually cast moulds in both pinnae. Each mould had an access hole to the auditory canal. The absolute and algebraic, azimuth and elevation errors were measured for all subjects at each position of the source. The variability of azimuth and elevation error was also computed. The performance of the subjects was compared to their performance under normal hearing conditions. Insertion of the pinnae moulds was found to increase substantially elevation error and the number of front/back reversals. The importance of the cues provided by the pinnae in these discriminations was thus confirmed. However, the increase in elevation error did not result in a corresponding increase in azimuth error. These findings provide support for the proposition that azimuth and elevation discrimination are coded independently.
在去除耳廓提供的定位线索的条件下，测量方位和仰角辨别敏锐度。四名受试者对一个声源（通过扬声器发出的白噪声）进行定位，该声源在头部左侧的一系列仰角（-40度至+40度）和方位角（0度至180度）范围内以10度间隔变化位置。通过在两个耳廓中插入单独铸造的模具来去除耳廓线索。每个模具都有一个通向耳道的入口孔。在声源的每个位置测量所有受试者的绝对和代数方位角和仰角误差。还计算了方位角和仰角误差的变异性。将受试者的表现与其在正常听力条件下的表现进行比较。发现插入耳廓模具会大幅增加仰角误差和前后反转的次数。因此证实了耳廓提供的线索在这些辨别中的重要性。然而，仰角误差的增加并没有导致相应的方位角误差增加。这些发现为方位和仰角辨别是独立编码的这一命题提供了支持。
