Physiology And Mechanics Of Insect Hearing Organs

Tympanal hearing organs of insects emit distortion-product otoacoustic emissions (DPOAEs) which are indicative of nonlinear mechanical sound processing. General characteristics of insect DPOAEs are comparable to those measured in vertebrates, despite distinct differences in ear anatomy. DPOAEs appear during simultaneous stimulation with two pure tones (f1

Insect Hearing provides a broadly based view of the functions, mechanisms, and evolution of hearing in insects. With a single exception, the chapters focus on problems of hearing and their solutions, rather than being focused on particular taxa. The exception, hearing in Drosophila, is justified because, due to its ever growing toolbox of genetic and optical techniques, Drosophila is rapidly becoming one of the most important model systems in neurobiology, including the neurobiology of hearing. Auditory systems, whether insectan or vertebrate, must perform a number of basic tasks: capturing mechanical stimuli and transducing these into neural activity, representing the timing and frequency of sound signals, distinguishing between behaviorally relevant signals and other sounds and localizing sound sources. Studying how these are accomplished in insects offers a valuable comparative view that helps to reveal general principles of auditory function.

This volume provides a comprehensive selection of recent studies addressing insect hearing and acoustic communication. The variety of signalling behaviours and hearing organs makes insects highly suitable animals for exploring and analysing signal generation and hearing in the context of neural processing, ecology, evolution and genetics. Across a variety of hearing species like moths, crickets, bush-crickets, grasshoppers, cicadas and flies, the leading researchers in the field cover recent scientific progress and address key points in current research, such as: - How can we approach the evolution of hearing in insects and what is the developmental and neural origin of the auditory organs? - How are hearing and sound production embedded in the natural lifestyle of the animals, allowing intraspecific communication but also predator avoidance and even predation? - What are the functional properties of hearing organs and how are they achieved at the molecular, biophysical and neural levels? - What are the neural mechanisms of central auditory processing and signal generation? The book is intended for students and researchers both inside and outside of the fascinating field of bioacoustics and aims to foster understanding of hearing and acoustic communication in insects.

The Springer Handbook of Auditory Research presents a series of compre hensive and synthetic reviews of the fundamental topics in modern auditory research. The volumes are aimed at all individuals with interests in hearing research, including advanced graduate students, postdoctoral researchers, and clinical investigators. The volumes are intended to introduce new in vestigators to important aspects of hearing science and to help established investigators to better understand the fundamental theories and data in fields of hearing that they may not normally follow closely. Each volume is intended to present a particular topic comprehensively, and each chapter serves as a synthetic overview and guide to the literature. As such, the chapters present neither exhaustive data reviews nor original research that has not yet appeared in peer-reviewed journals. The volumes focus on topics that have developed a solid data and conceptual foundation, rather than on those for which a literature is only beginning to develop. New research areas will be covered on a timely basis in the series as they begin to mature.

While we may have always assumed that insects employ auditory communication, our understanding of it has been impeded by various technical challenges. In comparison to the study of an insect's visual and olfactory expression, research in the area of acoustic communication has lagged behind. Filling this void, Insect Sounds and Communication is the

Investigating how insects receive sound via the structure of their auditory organs could inspire new, more sensitive, acoustic sensor systems to be developed, where the insect hearing organs that have previously been documented are believed to be more sensitive than any man-made devices that can currently be made. Firstly though, the structure and functioning of the biological inspiration, insect tympanal hearing organs, have to be more fully understood. This Thesis research firstly investigated the biomechanical properties of the tympanal membrane of various species and orders of insect using laser Doppler vibrometry. The results were then compared between species, including the different structures and also the membrane mechanics. This chapter results highlights the different structures and also the range of frequencies that each species is tuned to. By comparing the tympanal organs shape and the mechanics on the membrane surface caused by the received sound waves hopefully this can be applied to future membrane design. Some species of insect have been found to have active hearing characteristics, in order to understand the functioning of these hearing organs these were investigated using different methods to previous studies to try and identify the origin of the active hearing. In previous studies these characteristics were recorded acoustically from the tympanal organs of a number of species. The current study aimed to record the vibration created by the emissions through the membrane this was investigated in both locust and moth tympanal organs. No active hearing characteristics were recordable on the surface of the membrane. Finally both laser vibrometry and electrophysiology recordings were used to investigate very high frequency sensitivity of a moth hearing organ. The findings have greatly extended the known range of hearing in insects. The moth hearing organ is capable of receiving and processing frequencies up to 300 kHz with a very simple tympanal organ. This discovery could inspire smaller and simpler designs of transducers at ultrasonic frequencies. Overall this thesis work demonstrates the amazing sensitivity of the insect tympanal organs and takes steps toward further understanding of the auditory processing in insect tympanal organs.

Basic Mechanisms in Hearing is a collection of papers that discusses the function of the auditory system covering its ultrastructure, physiology, and the mechanism's connection with experimental psychology. Papers review the mechanics, morphology, and physiology of the cochlear, including the physiology of individual hair cells and their synapses. One paper examines the combined physiological and anatomical studies of stimulus coding in the mammalian auditory nervous system. The results of these studies pertain to the latency, frequency selectivity, and time pattern of responses to short tone bursts. Other research compare the cochlear nerve, behavioral, and psychophysical frequency selectivity which show that frequency selectivity of the auditory system occurs at the level of the cochlear nerve, becoming downgraded in end-organ deafness. Other papers discuss neural coding at higher levels such as the feature extraction in the auditory system of bats. Some papers also analyze the specialized hearing mechanisms in animals, for example, the echolocation of bats and in some insects, the function of the swimbladder in fish hearing, as well as the "invertebrate frequency analyzer" in the locust ear. Physiologists, neurophysiologists, neurobiologists, general medical practioners, and EENT specialists will find this collection valuable.

Advances in Insect Physiology, Volume 61 highlights new advances in the field, with this new volume presenting interesting chapters on a variety of timely topics, including Acoustic signaling in Orthoptera, Sound production in Drosophila melanogaster, and Communication by surface borne mechanical waves in insects. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in the Advances in Insect Physiology series

Reptiles and birds have highly diverse hearing organs. Data on a huge amount of information concerning all aspects of structural, neurophysiological and anatomical aspects are reviewed as published up to mid-1988: in addition a good deal of yet unpublished data from the author's laboratory are included. The literature on hearing is scattered through a great variety of zoological, medical, psychological, psychoacoustical and bioengineering journals: this book condenses all important findings in one source.