Auditory mechanics in a bush-cricket: direct evidence of dual sound inputs in the pressure difference receiver

The ear of the bush-cricket Copiphora gorgonensis consists of a system of paired eardrums (tympana) on each foreleg. In these insects, the ear is backed by an air-filled tube, the acoustic trachea (AT), which transfers sound from the prothoracic acoustic spiracle to the internal side of the eardrums. Both surfaces of the eardrums of this auditory system are exposed to sound, making it a directionally sensitive pressure-difference receiver. A key feature of the AT is its capacity to reduce the velocity of sound propagation and alter the acoustic driving forces at the tympanum. The mechanism responsible for reduction in sound velocity in the AT remains elusive, yet it is deemed to depend on adiabatic or isothermal conditions. To investigate the biophysics of such multiple input ears, we used micro-scanning laser Doppler vibrometry and micro-computed X-ray tomography. We measured the velocity of sound propagation in the acoustic trachea, the transmission gains across auditory frequencies, and the time-resolved mechanical dynamics of the tympanal membranes in Copiphora gorgonensis. Tracheal sound transmission generates a gain of ~15 dB SPL, and a propagation velocity of ca. 255 m/s, a ~25% reduction from free field propagation. Modelling tracheal acoustic behaviour that accounts for thermal and viscous effects, we conclude that reduction in sound velocity within the acoustic trachea can be explained, amongst 34 others, by heat exchange between the sound wave and the tracheal walls

REPERTORIUM VAN TIJDSCHRIFTLITERATUUR OP HET GEBIED VAN ACCOUNTANCY EN BEDRIJFSHUISHOUDKUNDE A. ACCOUNTANCY LEER VAN DE INRICHTING

REPERTORIUM VAN TIJDSCHRIFTLITERATUUR OP HET GEBIED VAN ACCOUNTANCY EN BEDRIJFSHUISHOUDKUNDE A. ACCOUNTANCY LEER VAN DE INRICHTIN

Trimethylacetic Formic Anhydride - Improved Preparation and Use as a Highly Efficient and Selective N-Formylating Reagent

Contains fulltext : 10322.pdf (publisher's version ) (Open Access

Poly(Iminomethylenes) .8. Circular Insertion Mechanism of Nickel(Ii)-Catalyzed Polymerization of Isocyanides

Contains fulltext : 10283.pdf (publisher's version ) (Open Access

Poly(Iminomethylenes) .21. Synthesis of Copolymers of Isocyanides Derived from Alanylserine and Alanylhistidine

Contains fulltext : 10043.pdf (publisher's version ) (Open Access

A Molecular Cation Channel

Contains fulltext : 10306.pdf (publisher's version ) (Open Access

Synthesis, Spectroscopy and Polymerization of Methyl Alpha-[C-13,N-15]Isocyano)Propionate - Acetic Formic Anhydride as N-Formylating Reagent

Contains fulltext : 10324.pdf (publisher's version ) (Open Access

Synthesis and Magnetic-Properties of a Rigid High-Spin Density Polymer with Piperidine-N-Oxyl Pending Groups

Contains fulltext : 10097.pdf (publisher's version ) (Open Access

Evidence of an Ordered Columnar Mesophase in Peripherally Octa-N-Alkoxy-Substituted Phthalocyanines

Contains fulltext : 10348.pdf (publisher's version ) (Open Access

Asymmetrically Substituted Liquid-Crystalline Phthalocyanines and Side-Chain Polymers Derived from Them

Contains fulltext : 10557.pdf (publisher's version ) (Open Access