Data from: Frequency tuning and directional sensitivity of tympanal vibrations in the field cricket Gryllus bimaculatus

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.