TRAVELING-WAVE VELOCITY IN HUMAN COCHLEA

When two equally loud tones of somewhat different frequency are simultaneously pulsed and presented, one to each ear, a single coherent tonal image can be heard lateralized toward the higher frequency side. When the higher frequency signal is delayed by an appropriate amount, the sound image is brought to the midline. According to place theory, the two different frequencies are now arriving simultaneously at their designated places on the cochlear partition. A number of such tonal pairs were used to determine traveling wave velocity along various short segments of cochlear partition. Averaged estimates from three trained listeners showed wave velocity decreasing from about 30 m/sec on the higher frequency portion of the partition to approximately 1.0 m/sec near the low frequency end. Our results are compared with some psychophysical and electrophysiological findings. © 1969, Acoustical Society of America. All rights reserved.