Anatomic and acoustic sexual dimorphism in the sound emission system of Phoenicoprocta capistrata (Lepidoptera: Arctiidae).

Both sexes of Phoenicoprocta capistrata have functional tymbals. The scanning electron microscopy revealed differences in the morphology of these organs in males and females. Male tymbals have a well-developed striated band, constituted by 21 +/- 2 regularly arranged striae whereas female tymbals lack a striated band.

Otoacoustic emissions from insect ears having just one auditory neuron.

Sensitive hearing organs often employ nonlinear mechanical sound processing which produces distortion-product otoacoustic emissions. Such emissions are also recorded from insect tympanal organs. Here we report high frequency distortion-product emissions, evoked by stimulus frequencies up to 95 kHz, from the tympanal organ of a notodontid moth, Ptilodon cucullina, which contains only a single auditory receptor neuron.

L1,L2 maps of distortion-product otoacoustic emissions from a moth ear with only two auditory receptor neurons.

The tympanal organ of the moth Empyreuma affinis emits physiologically vulnerable distortion-product otoacoustic emissions. To assess the nature of underlying mechanical nonlinearities, we measured L1,L2 maps by varying both stimulus levels. Two types of maps were found: (1) Maps containing dominant islands centered at the L1=L2 diagonal as it is typical for saturating nonlinearities that can be described by Boltzmann functions.

Threshold minima and maxima in the behavioral audiograms of the bats Artibeus jamaicensis and Eptesicus fuscus are not produced by cochlear mechanics.

Behavioral audiograms of Artibeus jamaicensis and Eptesicus fuscus are characterized by two threshold minima separated by a threshold maximum at 40 kHz, for A. jamaicensis, and 45 kHz, for E. fuscus [Koay, G.