Xv. Communications Biophysics

When a brief auditory stimulus is presented to the ear of an anesthetized cat, an electrode placed near the round window of the cochlea will detect a response of the sort represented in Fig. XV-la. A second electrode, placed on the auditory cortex, records a response whose time course is indicated in Fig. XV-lb. There has been a considerable amount of interest in both the amplitude and latency of the peaks that occur in these responses (2, 3, 4). The method heretofore employed in these measurements photographing from an oscilloscope and measuring on a microfilm reader is time-consuming and effectively limits the collection of data. In an attempt to achieve more rapid analysis, an amplitude quantizer (5) and a latency measuring instrument (6) were constructed in 1954. The usefulness of these early models was seriously impaired by limited resolving power on the one hand, and inconvenient operation and display on the other. Consequently, a new instrument, measuring both latency and amplitude, was developed.