Early predator detection is a key component of the predator-prey arms race and has driven the evolution of multiple animal hearing systems. Katydids (Insecta) have sophisticated ears, each consisting of paired tympana on each foreleg that receive sound both externally, through the air, and internally via a narrowing ear canal running through the leg from an acoustic spiracle on the thorax. These ears are pressure-time difference receivers capable of sensitive and accurate directional hearing across a wide frequency range. Many katydid species have cuticular pinnae which form cavities around the outer tympanal surfaces, but their function is unknown. We investigated pinnal function in the katydid Copiphora gorgonensis by combining experimental biophysics and numerical modelling using 3D ear geometries. We found that the pinnae in C. gorgonensis do not assist in directional hearing for conspecific call frequencies, but instead act as ultrasound detectors. Pinnae induced large sound pressure gains (20–30 dB) that enhanced sound detection at high ultrasonic frequencies (>60 kHz), matching the echolocation range of co-occurring insectivorous gleaning bats. These findings were supported by behavioural and neural audiograms and pinnal cavity resonances from live specimens, and comparisons with the pinnal mechanics of sympatric katydid species, which together suggest that katydid pinnae primarily evolved for the enhanced detection of predatory bats.

Please see the README document ("README_Pinnae.txt") and the accompanying published article: 

Pulver, C., Celiker, E., Woodrow, C., Geipel, I., Soulsbury, C.D., Cullen, D.A., Rogers, S.M., Veitch, D., Montealegre-Z, F. Ear pinnae in a neotropical katydid (Orthoptera: Tettigoniidae) function as ultrasound guides for bat detection. eLife 11:e77628. 

The dataset was collected from three different methods used in the publication: laser Doppler vibrometry (LDV), numerical simulations, and micro-CT. The LDV data consists of ASCII (.txt) files from recordings on live specimes and 3D prints.  The files are composed of time and frequency domain recordings.  Microsoft Excel sheets with ASCII file inputs are provided if .txt not uploaded.  The numerical simulations consists of FEA files for each specimen and compressed.  The micro-CT data were uploaded as .stl files for each ear from experimental specimen. 

Laser Doppler vibrometry files require Polytec Software (.psv) if files have not been exported as ASCII .txt files or imported in Excel.  

Numerical simulation files require COMSOL software.

Data are in formats easily readable by common programs.