Tympanal membrane motion is necessary for hearing in crickets

1. Sound guided through the tracheal tube to the internal tracheal spaces in the region of the cricket ear is capable of eliciting auditory neural responses in the prothoracic ganglion if the tympanal membrane is allowed to vibrate freely. If the tympanal membrane motion is prevented mechanically neural responses are abolished (Fig. 3) whereas the sound pressure in the tracheal air spaces behind the tympanum is increased. 2. If the motion of the tympanum, as measured with laser vibrometry, is prevented by adjusting the internal and external sound pressure, then neural responses cease simultaneously (Fig. 5). 3. These findings demonstrate that motion of the large tympanum is a necessary requisite in the sound transduction process of the cricket ear.