02082nas a2200181   4500008004100000022001400041245012000055210006900175260002000244300001300264490000700277520137400284100002501658700002101683700002501704700002701729856014401756       2017                        eng d  a1742-568900aFrequency tuning and directional sensitivity of tympanal vibrations in the field cricket <i>Gryllus bimaculatus</i>0 aFrequency tuning and directional sensitivity of tympanal vibrati  cDec-28-20172018  a201700350 v143 a<p>Female field crickets use phonotaxis to locate males by their calling song. Male song production and female behavioural sensitivity form a pair of matched frequency filters, which in Gryllus bimaculatus are tuned to a frequency of about 4.7 kHz. Directional sensitivity is supported by an elaborate system of acoustic tracheae, which make the ears function as pressure difference receivers. As a result, phase differences between left and right sound inputs are transformed into vibration amplitude differences. Here we critically tested the hypothesis that acoustic properties of internal transmissions play a major role in tuning directional sensitivity to the calling song frequency, by measuring tympanal vibrations as a function of sound direction and frequency. Rather than sharp frequency tuning of directional sensitivity corresponding to the calling song, we found broad frequency tuning, with optima shifted to higher frequencies. These findings agree with predictions from a vector summation model for combining external and internal sounds. We show that the model provides robust directional sensitivity that is, however, broadly tuned with an optimum well above the calling song frequency. We therefore advocate that additional filtering, e.g. at a higher (neuronal) level, significantly contributes to frequency tuning of directional sensitivity.</p>
1 aLankheet, Martin, J.1 aCerkvenik, Uroš1 aLarsen, Ole, Næsbye1 avan Leeuwen, Johan, L.  uhttp://rsif.royalsocietypublishing.org/lookup/doi/10.1098/rsif.2017.0035https://syndication.highwire.org/content/doi/10.1098/rsif.2017.0035