FIG. 1.

A Lateral view of the right outer ear of a rabbit. The downward arrow points to a slit in the outer ear that is used as a benchmark to measure the ear length and interaural distance. B Same lateral view as in A with a superposed view of a cast made from dental impression material (Reprosil) to show the deeper, hidden part of the outer ear air cavity. The approximate position of the tympanum is also shown. Cross-sections of the cast at four levels are shown in the right part of panelB. The deepest section shows an embedded miniature microphone (Knowles FG-3329, 2.5-mm diameter × 2.6 mm length) used to measure the acoustic signals in a blocked meatus approach. Scale bar is 20 mm divided into 5 mm sections.