scholarly journals What is the sound of fear? Behavioral responses of white-crowned sparrows Zonotrichia leucophrys to synthesized nonlinear acoustic phenomena

2014 ◽  
Vol 60 (4) ◽  
pp. 534-541 ◽  
Author(s):  
Ellen K. Blesdoe ◽  
Daniel T. Blumstein
Keyword(s):  
Pure Tone ◽  
Wildlife Conservation ◽  
Sound Production ◽  
Behavioral Responses ◽  
Acoustic Properties ◽  
Nonlinear Phenomena ◽  
Adaptive Responses ◽  
Zonotrichia Leucophrys ◽  
Frequency Jump ◽  
Animal Vocalizations

Abstract Fear and anxiety may be adaptive responses to life-threatening situations, and animals may communicate fear to others vocally. A fundamental understanding of fear inducing sounds is important for both wildlife conservation and management because it helps us understand how to design repellents and also how (and why) animals may be negatively impacted by anthropogenic sounds. Nonlinear phenomena—sounds produced by the desynchronization of vibrations in a sound production system—are commonly found in stress-induced animal vocalizations, such as in alarm calls, mobbing calls, and fear screams. There are several functional hypotheses for these nonlinear phenomena. One specific hypothesis is the unpredictability hypothesis, which suggests that because nonlinear phenomena are more variable and somewhat unpredictable, animals are less likely to habituate to them. Animals should, therefore, have a prolonged response to sounds with nonlinear phenomena than sounds without them. Most of the studies involving nonlinear phenomena have used mammalian subjects and conspecific stimuli. Our study focused on white-crowned sparrows (Zonotrichia leucophrys ssp. oriantha) and used synthesized acoustic stimuli to investigate behavioral responses to stimuli with and without nonlinear phenomena. We predicted that birds would be less relaxed after hearing a stimulus with a nonlinear component. We calculated the difference from baseline of proportion of time spent in relaxed behaviors and performed pair-wise comparisons between a pure tone control stimulus and each of three experimental stimuli, including a frequency jump up, a frequency jump down, and white noise. These comparisons showed that in the 30‒60 s after the playback experiment, birds were significantly less relaxed after hearing noise or an abrupt frequency jump down an octave but not an abrupt frequency jump up an octave or a pure tone. Nonlinear phenomena, therefore, may be generally arousing to animals and may explain why these acoustic properties are commonly found in animal signals associated with fear [Current Zoology 60 (4): 534–541, 2014].

Une nouvelle méthode de mesure de la fonction d'aire du conduit vocal : cas des voyelles

2005 ◽  
Vol 83 (7) ◽  
pp. 721-737
Author(s):  
H Teffahi ◽  
B Guerin ◽  
A Djeradi
Keyword(s):  
Measurement Method ◽  
Cross Correlation ◽  
Sound Production ◽  
Linear Prediction ◽  
Vocal Tract ◽  
Random Sequence ◽  
Speech Sound ◽  
Acoustic Properties ◽  
External Excitation ◽  
White Noise Excitation

Knowledge of vocal tract area functions is important for the understanding of phenomena occurring during speech production. We present here a new measurement method based on the external excitation of the vocal tract with a known pseudo-random sequence, where the area function is obtained by a linear prediction analysis applied to the cross-correlation between the sequence and the signal measured at the lips. The advantages of this method over methods based on sweep-tones or white noise excitation are (1) a much shorter measurement time (about 100 ms) and (2) the possibility of speech sound production during the measurement. This method has been checked against classical methods through systematic comparisons on a small corpus of vowels. Moreover, it has been verified that simultaneous speech sound production does not perturb significantly the measurements. This method should thus be a very helpful tool for the investigation of the acoustic properties of the vocal tract in various cases for vowels.

The Mechanics of Stridulation in Bush Crickets (Tettigonioidea, Orthoptera)

1970 ◽  
Vol 52 (3) ◽  
pp. 495-505 ◽  
Author(s):  
W. J. BAILEY
Keyword(s):  
Detailed Analysis ◽  
Pure Tone ◽  
Sound Production ◽  
Sound Radiation ◽  
Rotational Axis ◽  
The Right ◽  
Bush Crickets

1. A method has been devised by which the isolated tegmina of bush crickets can be actuated in such a manner as to simulate the insect's natural song. 2. The actuator was used to make a detailed analysis of the mechanics of sound production, with particular reference to the emission of the more or less pure tone at 15 kHz., characteristic of Homorocoryphus nitidulus. 3. Results involving damping and cautery indicated that the area of the right tegmen responsible for the radiation of this sound was the mirror frame, the vein enclosing the classical mirror membrane. 4. Further experiments involving transduced sound and a probe microphone led to the construction of sound radiation maps of the right tegmen which supported the above view. 5. The cantilever hypothesis, involving the mirror frame with the axis of the vestigial file as the cantilever's rotational axis, was considered in the light of the Homorocoryphus type. 6. The Homorocoryphus type differed from the Conocephalus type (on which the cantilever hypothesis was based) in that a simpler cantilever is formed in a line direct from the plectrum to the tip of the frame arm.

scholarly journals Birdsong and Sound Transmission: The Benefits of Reverberations

The Condor ◽  
2002 ◽  
Vol 104 (3) ◽  
pp. 564-573 ◽  
Author(s):  
Hans Slabbekoorn ◽  
Jacintha Ellers ◽  
Thomas B. Smith
Keyword(s):  
Bird Species ◽  
Sound Transmission ◽  
Acoustic Properties ◽  
Signal Design ◽  
Signal Attenuation ◽  
Long Distance ◽  
Animal Vocalizations ◽  
Distance Communication ◽  
The Relationship ◽  
Insight Into

Abstract Animal vocalizations used for long-distance communication are shaped by acoustic properties of the environment. Studies of the relationship between signal design and sound transmission typically focus on habitat-induced limitations due to signal attenuation and degradation. However, signal design may not entirely be explained by habitat limitations, but rather by beneficial consequences of reverberations. Narrow-frequency bandwidth notes (NFB notes) are pure notes that change little in frequency, and are typical for many bird species living in dense tropical forests. In contrast to frequency-modulated notes, we show that reverberations lead to a longer and louder signal after transmission for NFB notes. Furthermore, playback experiments to territorial males of an African passerine indicated that longer notes led to a stronger behavioral response. These results suggest that reverberations may benefit signal efficiency depending on the signal design, and add new insight into the selection pressures imposed on acoustic signals by the environment. Canto de Aves y Transmisión de Sonido: Beneficios de las Reverberaciones Resumen. Las vocalizaciones utilizadas por animales para la comunicación a larga distancia están condicionadas por las propiedades acústicas del entorno. Los estudios sobre la relación entre el diseño de las señales y la transmisión del sonido suelen centrarse en los límites impuestos por el hábitat debido a la atenuación y degradación de la señal. Sin embargo, es posible que el diseño de la señal no esté regido exclusivamente por las limitaciones del habitat, sino por las consecuencias beneficiosas de las reverberaciones. Las notas de frecuencia de banda estrecha (notas NFB) son notas puras que cambian poco de frecuencia y son típicas de varias especies que habitan bosques tropicales densos. Al contrario que en las notas de frecuencia modulada, mostramos que las reverberaciones alargan y aumentan la señal de las notas NFB. Asimismo, experimentos de playback con machos territoriales de un paseriforme africano indican que las notas más largas provocan una mayor respuesta. Estos resultados sugieren que las reverberaciones pueden mejorar la eficiencia de la señal, dependiendo del diseño de la misma, y añaden un nuevo componente a nuestro conocimiento sobre las presiones selectivas impuestas por el entorno sobre las señales acústicas.

scholarly journals Resonators in insect sound production: how insects produce loud pure-tone songs

1999 ◽  
Vol 202 (23) ◽  
pp. 3347-3357 ◽  
Author(s):  
H.C. Bennet-Clark
Keyword(s):  
Pure Tone ◽  
Sound Production ◽  
Slow Muscle ◽  
Frequency Multiplier ◽  
Contraction Rate ◽  
Mechanical Resonator ◽  
Second Stage ◽  
Different Types ◽  
Song Frequency ◽  
Slow Contraction

In a resonant vibration, two reactive elements, such as a mass and a spring, interact: the resonant frequency depends on the magnitude of these two elements. The build-up and decay of the vibration depend on the way the resonator is driven and on the damping in the system. The evidence for the existence of resonators in insect sound production is assessed. The mechanics of different types of sound-producing system found in insects is described. Mechanical frequency-multiplier mechanisms, which convert the relatively slow contraction of muscles to the higher frequency of the sound, are commonly used to convert the comparatively slow muscle contraction rate to the higher frequency of the sound. The phasing and rate of mechanical excitation may also affect the frequency and duration of the sound that is produced. Although in many insects the song may appear to be produced by the excitation of a simple resonator, the song frequency may not be constant, suggesting that other factors, such as the mechanism of excitation, or variation of the effective mass or elasticity of the system during sound production, may be additional determinants of the song frequency. Loud, and hence efficient, transduction of the energy of a mechanical resonator into sound may involve a second stage of transduction which, by damping the resonator, may compromise tonal purity. Some insect singers resolve this problem by tuning both stages of transduction to the same frequency, thereby maintaining tonal purity.

scholarly journals Experimental characterization and automatic identification of stridulatory sounds inside wood

2021 ◽  
Author(s):  
Carol L. Bedoya ◽  
Ximena J. Nelson ◽  
Eckehard G. Brockerhoff ◽  
Stephen Pawson ◽  
Michael Hayes
Keyword(s):  
Bark Beetles ◽  
Sound Production ◽  
Automatic Identification ◽  
Spectral Parameters ◽  
Detection And Identification ◽  
Distance Dependence ◽  
Animal Vocalizations ◽  
Automatic Methods ◽  
Spectral Ranges ◽  
Wood Boring

ABSTRACTThe propagation of animal vocalizations in water and in air is a well-studied phenomenon, but sound produced by bark and wood boring insects, which feed and reproduce inside trees, is poorly understood. Often being confined to the dark and chemically-saturated habitat of wood, many bark- and woodborers have developed stridulatory mechanisms to communicate acoustically. Despite their ecological and economic importance and the unusual medium used for acoustic communication, very little is known about sound production in these insects, or their acoustic interactions inside trees. Here, we use bark beetles (Scolytinae) as a model system to study the effects of wooden tissue on the propagation of insect stridulations and propose algorithms for their automatic identification. We characterize distance-dependence of the spectral parameters of stridulatory sounds, propose data-based models for the power decay of the stridulations in both outer and inner bark, provide optimal spectral ranges for stridulation detectability, and develop automatic methods for their detection and identification. We also discuss the acoustic discernibility of species cohabitating the same log. The species tested can be acoustically identified with 99% of accuracy at distances up to 20 cm and detected to the greatest extent in the 2-6 kHz frequency band. Phloem was a better medium for sound transmission than bark.

The role of the tymbal in cicada sound production

1995 ◽  
Vol 198 (4) ◽  
pp. 1001-1020 ◽  
Author(s):  
D Young ◽  
H Bennet-Clark
Keyword(s):  
Sound Production ◽  
Muscle Power ◽  
Maximum Amplitude ◽  
Dominant Frequency ◽  
Acoustic Properties ◽  
Muscle Shortening ◽  
Frequency Changes ◽  
Work Supports ◽  
Peak Value

1. The tymbal of Cyclochila australasiae consists of a biconvex membrane bearing alternating long and short ribs anteriorly and an irregularly shaped tymbal plate posteriorly. These sclerotised regions are coupled together by the surrounding highly flexible cuticle, which contains resilin. Dorsally, there is a thick pad of resilin, which functions as a spring, returning the tymbal to the out position and maintaining the stress on the long ribs. 2. Contraction of the tymbal muscle causes the tymbal plate to swing inwards, acting as a lever so that the surface of the tymbal moves through more than twice the distance of muscle shortening. This produces an inward movement and twisting of the dorsal ends of the long ribs, which then buckle in sequence, with each rib undergoing a sudden deformation from a convex to a V-shaped profile. Buckling takes place at the rib's weakest point, which is the narrow, highly sclerotised mid-region. 3. Inward buckling of the tymbal generates a loud click with a dominant frequency around 4 kHz. Resonances close to 4 kHz can be demonstrated in a buckled-in tymbal when driven by internal sound or by vibration at the tymbal plate. These resonances occur in sealed cicadas and those in which the abdominal air sac has been opened at both its anterior and posterior ends, which shows that the resonances are not due to the air sac; the tymbal itself is a resonant system. The maximum amplitude of tymbal vibration occurs at the V-shaped dimples in the centre of the long ribs. 4. When the tymbal plus abdominal air sac system is driven by vibration at the tymbal plate, the Q3dB of the sound radiated through the tympana is about 12.5, which is approximately the sum of those of the tymbal (Q=9.3) and of the air sac (Q=3.4) resonators. When the tymbal is not loaded by the air sac, i.e. in the sealed cicada and open cicada preparations, the Q3dB of its resonance is higher, between 13 and 20. 5. The click produced as the tymbal pops out is over 20 dB quieter than the in-click and has a dominant frequency around 6 kHz. When driven in the resting position, resonances are found close to 6 kHz but there is only a weak general vibration of the ribs and tymbal plate. When the tymbal is pushed in gradually, the resonant frequency changes from about 5.5 kHz to about 4.3 kHz as the tymbal buckles inwards. The left and right tymbals of the same insect may differ slightly in their acoustic properties. 6. As the tymbal buckles inwards, it displaces a volume of approximately 6 µl into the abdominal air sac volume of about 2 ml. The resulting sound pressure inside the air sac attains peak values of 155­159 dB SPL; the root mean square values are 141­144 dB SPL. The mean peak value just outside the tympana is 148.5 dB SPL. 7. Overall, the present work supports and extends our earlier model of cicada sound production: the tymbal click provides a coherent resonant source that drives the abdominal resonator, from which sound is radiated via the tympana. At the same time, the system provides the pressure transformation between muscle power and sound power that is desirable for efficient sound radiation.

Controlled Exposure Experiments to Determine the Effects of Noise on Marine Mammals

2003 ◽  
Vol 37 (4) ◽  
pp. 41-53 ◽  
Author(s):  
Peter Tyack ◽  
Jonathan Gordon ◽  
David Thompson
Keyword(s):  
Marine Mammals ◽  
Wildlife Conservation ◽  
Applied Research ◽  
Behavioral Responses ◽  
Critical Element ◽  
Underwater Noise ◽  
Playback Experiments ◽  
Controlled Exposure ◽  
Acoustic Exposure ◽  
The Relationship

Controlled exposure experiments or CEEs are an important technique for determining the responses of animals to signals that are not part of their own communicative repertoire. CEEs are useful for establishing the relationship between acoustic dosage and behavioral response, a critical element of risk assessment, similar to dose:response studies for exposure to chemicals. CEEs share some properties with “playback” experiments; the main difference between playbacks and CEEs is that CEEs involve the careful titration of acoustic exposure to the point where specific responses are observed. Most CEEs are applied research designed to answer questions related to wildlife conservation. The utility and power of CEEs lies in providing a sensitive measure of causal relationships between behavioral responses and particular stimuli. We review design features and experimental methods for CEEs, limiting our scope for this paper to studying the effects of underwater noise on wild marine mammals.

scholarly journals How Loud Can you go? Physical and Physiological Constraints to Producing High Sound Pressures in Animal Vocalizations

2021 ◽  
Vol 9 ◽  
Author(s):  
Lasse Jakobsen ◽  
Jakob Christensen-Dalsgaard ◽  
Peter Møller Juhl ◽  
Coen P. H. Elemans
Keyword(s):  
Sound Production ◽  
Sound Propagation ◽  
Sound Field ◽  
Sperm Whale ◽  
Mammal Species ◽  
Sound Communication ◽  
Physiological Limits ◽  
Non Linear ◽  
Animal Vocalizations ◽  
High Sound

Sound is vital for communication and navigation across the animal kingdom and sound communication is unrivaled in accuracy and information richness over long distances both in air and water. The source level (SL) of the sound is a key factor in determining the range at which animals can communicate and the range at which echolocators can operate their biosonar. Here we compile, standardize and compare measurements of the loudest animals both in air and water. In air we find a remarkable similarity in the highest SLs produced across the different taxa. Within all taxa we find species that produce sound above 100 dBpeak re 20 μPa at 1 m, and a few bird and mammal species have SLs as high as 125 dBpeak re 20 μPa at 1 m. We next used pulsating sphere and piston models to estimate the maximum sound pressures generated in the radiated sound field. These data suggest that the loudest species within all taxa converge upon maximum pressures of 140–150 dBpeak re 20 μPa in air. In water, the toothed whales produce by far the loudest SLs up to 240 dBpeak re 1 μPa at 1 m. We discuss possible physical limitations to the production, radiation and propagation of high sound pressures. Furthermore, we discuss physiological limitations to the wide variety of sound generating mechanisms that have evolved in air and water of which many are still not well-understood or even unknown. We propose that in air, non-linear sound propagation forms a limit to producing louder sounds. While non-linear sound propagation may play a role in water as well, both sperm whale and pistol shrimp reach another physical limit of sound production, the cavitation limit in water. Taken together, our data suggests that both in air and water, animals evolved that produce sound so loud that they are pushing against physical rather than physiological limits of sound production, radiation and propagation.

Review of bioacoustical traits in the genus Physalaemus Fitzinger, 1826 (Anura: Leptodactylidae: Leiuperinae)

Zootaxa ◽  
2020 ◽  
Vol 4725 (1) ◽  
pp. 1-106
Author(s):  
FÁBIO HEPP ◽  
JOSÉ P. JR. POMBAL
Keyword(s):  
Fundamental Frequency ◽  
Frequency Modulation ◽  
Complex Traits ◽  
Principal Component ◽  
Dominant Frequency ◽  
Acoustic Properties ◽  
Nonlinear Phenomena ◽  
Mating Activity ◽  
Call Type ◽  
Frequency Bands

Given the importance of acoustic communication in intraspecific recognition during mating activity, acoustic traits have been widely used to clarify the taxonomy of anurans. They have been particularly useful in the study of taxa with high morphological similarity such as the Neotropical genus Physalaemus. Here, we reviewed the acoustic repertoires of the species of Physalaemus based on homology hypotheses in order to make comparisons more properly applicable for taxonomic purposes. We covered all the known clades and species groups for the genus, analyzing 45 species (94 % of the currently recognized taxa). Different call types were labeled with letters (i.e., A, B, and C) to avoid speculative functional propositions for the call types. In order to identify correctly the observed frequency bands, we propose a method to interpret them based on the predicted graphic behavior on audiospectrogram and on the mathematic relationship among bands considering each kind of band production (e.g., harmonics and sidebands). We found different acoustic traits between the major clades P. signifer and P. cuvieri. Species in the P. signifer clade have more than one call type (67 % of species in the clade). Furthermore, all species of this clade have A calls with pulses and/or low fundamental frequency (< 500 Hz). In the P. cuvieri clade, species emit only one call type and, in most species, this call is a continuous whine-like emission with relatively high fundamental frequency (> 400 Hz) and several S-shaped harmonics (except for species of P. henselii and P. olfersii groups, P. centralis, and P. cicada). Within the P. signifer clade, pulsed calls are present in P. angrensis, P. atlanticus, P. bokermanni, P. crombiei, P. irroratus, P. moreirae, P. nanus, and P. obtectus, whereas within the P. cuvieri clade this feature is restricted to a few species (10 % of the clade): P. jordanensis, P. feioi, and P. orophilus. A principal component analysis of the quantitative data indicates two clusters that substantially correspond to the composition of these two major clades with a few exceptions. Overall, the cluster composed of taxa of the P. signifer clade has lower fundamental frequency, bandwidth and dominant frequency at the end of the call and higher frequency delta and dominant frequency at the end of the call than the cluster with most taxa of the P. cuvieri clade. We also identified and described several similarities among acoustic signals of closely related species, which might correspond to synapomorphies in the evolution of the acoustic signal in the group. Species of the P. deimaticus group emit long sequences of very short A calls with low fundamental frequency (< 300 Hz) and short duration (< 0.2 s). Most species in the P. signifer group have clearly pulsed calls and emit at least two different call types. Species in the P. henselii group have calls with only high frequency bands (> 1700 Hz). Species in P. cuvieri group have continuous calls that resemble nasal-like sounds or whines, with downward frequency modulation. Species in the P. olfersii group emit long calls (> 1 s) with ascendant and periodic frequency modulation. Calls of the species in the P. biligonigerus and P. gracilis groups usually have continuous whine-like calls with call envelopes very variable within species. In addition, we describe traits in the genus for the first time, such as complex traits not predicted by simple and linear acoustic models (nonlinear phenomena), and discuss the application of acoustic traits to taxonomy and phylogenetics and morphological constraints of the vocal apparatus that might be related to the different acoustic properties found. 

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