@article {57939, title = {Stimulus transmission in the auditory receptor organs of the foreleg of bushcrickets (Tettigoniidae) I. The role of the tympana}, year = {1998}, abstract = {

The auditory organs of the tettigoniid are located just below the femoral tibial joint in the forelegs. Structurally each auditory organ consists of a tonotopically organized crista acustica and intermediate organ and associated sound conducting structures; an acoustic trachea and two lateral tympanic membranes located at the level of the receptor complex. The receptor cells and associated satellite structures are located in a channel filled with hemolymph fluid. The vibratory response characteristics of the tympanic membranes generated by sound stimulation over the frequency range 2\–40 kHz have been studied using laser vibrometry. The acoustic trachea was found to be the principal structure through which sound energy reached the tympana. The velocity of propagation down the trachea was observed to be independent of the frequency and appreciably lower than the velocity of sound in free space. Structurally the tympana are found to be partially in contact with the air in the trachea and with the hemolymph in the channel containing the receptor cells. The two tympana were found to oscillate in phase, with a broad band frequency response, have linear coherent response characteristics and small time constant. Higher modes of vibration were not observed. Measurements of the pattern of vibration of the tympana showed that these structures vibrate as hinged flaps rather than vibrating stretched membranes. These findings, together with the morphology of the organ and physiological data from the receptor cells, suggest the possibility of an impedance matching function for the tympana in the transmission of acoustic energy to the receptor cells in the tettigoniid ear.

}, doi = {10.1016/S0378-5955(97)00177-9}, url = {https://linkinghub.elsevier.com/retrieve/pii/S0378595597001779}, author = {Bangert, Marc and Kalmring, Klaus and Sickmann, Thomas and Stephen, Richard and Jatho, Martin and Lakes-Harlan, Reinhard} } @article {53567, title = {The coding of airborne-sound and vibration signals in bimodal ventral-cord neurons of the grasshopper Tettigonia cantans}, journal = {Journal of comparative physiology}, volume = {139}, year = {1980}, pages = {267{\textendash}275}, abstract = {

In grasshoppers, the auditory and vibra- tional senses converge on the same ventral-cord neurons. All neurons in the ventral cord that discharge impulses in response to either airborne-sound or vi- bration stimuli also receive synaptic inputs from the other sensory system. The latter elicit either sub- threshold excitation or inhibition.

The coding of the conspecific song in the responses of most ventral-cord neurons of Tettigonia cantans is considerably improved when the stimulus consists not of simulated natural sounds alone, but of such
sounds together with either maintained vibration or vibration matched to the temporal structure of the song.

Stridulating tettigoniids produce both airborne and substrate-conducted sound. Thus the perception of airborne sound and vibration, and their simulta- neous processing in individual ventral-cord neurons, may be of fundamental importance - not only in localizing a nearby sound source, but also in facilitat- ing the recognition of conspecific signals.

}, author = {Kalmring, Klaus and K{\"u}hne, Roland} }